stats: fix display when no data ready yet

* jQ uses .append(), not .appendChild()
* when no data ready, display a nice message
* rephrase the message, the data isn't ready, not hasn't loaded yet

docs/contributing: move 'roadmap' to the wiki

As the 'roadmap' is typically changed often, it should not be in the
documentation but rather on the wiki. The wiki has been updated to reflect
the latest version removed here.

docs: move all instructions on Celery to Setup

Instead of having some info on Celery in both Installation and Setup, move
everything to Setup and do some rewrite.

Additionally, update some outdated URLs and remove unused link targets.

docs/installation: clarify and reorder alternative installation methods

- Add an introduction describing the different installation methods and their
pros/cons.

- Clarify that Python 3.x is not currently supported.

- Move standard pip install method as last method, and rename as also in
virtualenv we are installing from Python Package Index.

docs/installation: add section on installation from repository source

As we actually recommend this method, describe it as first option in the
installation instructions.

README: link to readthedocs.org rather than python.org for documentation

The documentation at readthedocs.org is up-to-date with the latest revision,
while python.org shows the latest release.

ini file: clarify that beaker.session.key should be unique

When several instances of Kallithea are running on the same machine, the
same browser cannot be logged into both instances at the same time without
conflicts. The login session are saved into the same cookie; logging into
one instance closes the session on the second instance and vice-versa.

This is caused because the cookie name is simply 'kallithea', combined with
the fact that the cookie specification (RFC6265) states that there is no
isolation of cookies based on port. This means that the browser sends all
cookies from a given domain with all services (Kallithea instances) running
on that domain, irrespective of port.

The services thus need to handle any such issue themselves, for example by
using unique cookie names and only interacting with one's own cookie.

Making the key unique when creating the configuration file proved difficult:
- it does not seem possible to hook into 'paster make-config'
- since Beaker directly interprets the beaker.session.key, changing it on
the fly from SessionMiddleware will not work correctly.

There is a kallithea-config script that is an alternative to 'paster
make-config' which would be the ideal place to make such changes. However,
it seems this method is not advocated over 'paster make-config' (yet?).

Instead, simply add a comment in the config file and let the user take care
of it.

i18n: updated French translation using Weblate

Currently translated at 73.1% (788 of 1077 strings)

i18n: updated Czech translation using Weblate

Currently translated at 3.7% (40 of 1077 strings)

i18n: updated Japanese translation using Weblate

Currently translated at 99.8% (1075 of 1077 strings)

i18n: updated Japanese translation using Weblate

Currently translated at 99.8% (1075 of 1077 strings)

i18n: updated Japanese translation using Weblate

Currently translated at 99.8% (1075 of 1077 strings)

i18n: updated German translation using Weblate

Currently translated at 34.5% (372 of 1077 strings)

i18n: updated Russian translation using Weblate

Currently translated at 78.9% (850 of 1077 strings)

docs: rework stuff

The existing docs were far from how we wanted it to be. There was so much to do
and it is not feasible to do that cleanup it in clean patches.

Instead, I took a sweep through the docs and changed what I thought could
benefit from a change: structure, examples, advices, language, markup, content,
etc.

helpers: introduce user_or_none helper helper

Slight cleanup refactoring - will be useful later.

helpers: fix gravatar handling with (invalid) non-ascii email addresses

It would crash with UnicodeDecodeError when trying to expand unicode email into
utf8 template.

db: fix beaker caching key of (invalid) unicode email addresses

It would crash with UnicodeDecodeError in beaker when trying to retrieve the
user by email.

pullrequest overview: show age rather than date

Since pullrequests are supposed to be short-lived, the age is more relevant
than the actual date (which is still shown in a tooltip).

pullrequest overview: remove custom handling of 'my pullrequests'

Re-use the same displaying code for the 'my pullrequests' overview as for
the repository pullrequests overview. Remove the now unused CSS styling as
well.

This removes the 'delete' button on the author's pullrequests. One could
argue whether the pullrequest overview is the right place for this button,
while it does not appear on the pull request page itself.

pullrequest overview: add delete button to own pull requests

In anticipation of the re-use of the pullrequest overview to display 'my
pullrequests', add a delete button to all pullrequests owned by the
currently logged-in user.
An explicit width is added to the column because the column is otherwise
unnecessarily large.

pullrequest overview: create overview from a function to allow re-use

In anticipation of re-use of the pullrequest overview, create a def to
generate this overview given a list of pullrequests.

This also adds a check if the given list is empty, and a check if there is a
pager before displaying the paging links.

style: add class 'normal-indent' instead of repeated explicit margins

Add a new CSS class for the standard indentation inside the main box,
instead of repeating 'style="..."' statements on the relevant elements.

Ideally, this class should not exist as the necessary padding would be added
to the main box itself, but reworking this is a bigger exercise (to be done
later).

pullrequest overview: display in table to improve readability

Instead of showing all info in the pullrequest overview right after each
other on the same line, use a table to improve readability.

Additionally, add following information:
- author
- destination repository

The latter is always the same when viewing the list of pullrequests of a
certain repository, but this change already anticipates re-use of this
block in the 'my pullrequests' overview.

The table is still static, non-sortable, since YUI is deprecated and no new
alternative has been decided upon yet. This improvement can be done later.

date representation: use ISO8601 rather than a specific locale

Dates, in particular in technical systems like Kallithea, are
better shown in a clear concise format like ISO8601 (YYYY-MM-DD)
than in a verbose format like 'Thu, Feb 26 2015'.

This commit changes all dates to ISO8601.

---
If desired, we could create two functions: one that returns ISO format and
another for the locale format. Depending on the usage, one or the other is
shown. I'm not very fond of that though, it looks inconsistent.

vcs: better handling of closed subprocessio InputStreamChunker source stream

test_git_cmd_injection would fail occasionaly.

font: fix missing icon-comment-color and icon-comment-alt

We replace the font with our icon-comment one since we can color this with css.

templates: changelog_summary: remove non-existing CSS class table_disp

The changelog_summary template references a non-existing CSS class
table_disp. Remove it.

my pullrequests: line up controller/template handling with repo pullrequests

Currently, the data for 'my pullrequests' is loaded dynamically through
ajax, unlike the way 'repository pullrequests' are loaded (statically).

As there is no good reason to have both treated differently, and as dynamic
loading of 'my pullrequests' is not really needed, rework the handling of
the 'my pullrequests' page with the 'repository pullrequests' page.

This includes lining up the 'show closed pull requests' checkbox/link.

This also fixes issue #102 ('my pull requests' when not logged in:
incorrect handling of login).

pullrequest overview: sanitize display style

Remove the unnecessarily large font size on the pullrequest overview to line
up with the styling of 'my pullrequests'.

Additionally, add some whitespace between the 'show closed PRs' link and the
actual list.

controllers: don't pass rendered templates in context variables

Some controllers used the followifng pattern:
- render a data template into a context variable
- for partial (ajax) requests, return the contents of this variable
- for full-page requests, render the full page, which expands the value of
the context variable

Instead, avoid context variables let the controller simply render the full or partial page, and let
the full page template include the partial page.

Remove this context variable for templating and use render exclusively.
From templates, use %include instead of context variables.

This in line with the suggestions in the Pylons documentation:
http://pylons-webframework.readthedocs.org/en/latest/helpers.html#partial-updates-with-ajax

templates: move site branding in page title to base template

Instead of repeating the same three lines in each and every template, move
it to the base template.

pullrequests on different repos: default to same destination/source branch

When a pull request is initiated between two different repositories, instead
of using the current tip as destination branch, use the same branch as on
the source repository.

tests: move helper commit_change from compare test to fixture

Move the generic helper function _commit_change() to the fixture class,
allowing reuse by other test classes.

repository summary: avoid table bleed on long commit messages

For commit messages with the first line being very long, the 'latest
changes' table on the repository overview page can 'bleed', so that the
commit number overlaps with the commit status.

Commit 15cb8156b10d732cf39b37a88c656894621c0f54 changed the initial truncate
on 50 characters to a chop at the first newline characters, causing this
issue to pop up more frequently.

Instead of using floating divs for the commit status and number of comments,
use dedicated table columns, as compact as possible.
Additionally, move these new columns to the very left of the table, instead
of cramming them in between the revision and commit message.

The comments-container class gets a new attribute 'white-space: nowrap' to
avoid the comment icon to wrap from the number of comments, when the table
does wrap on a small screen.
Note that the icon currently does not display as it should be renamed from
icon-comment-alt/colored to icon-comment. This will be fixed by Sean Farley.

changelog: fix display artifacts in expanded multi-line commit messages

When a multi-line commit message is expanded in a changelog, and the last line
of the commit message has some characters that go below the baseline, like an
underscore, g, j, y, ... the bottom part of these characters would not be
shown.

This is caused by the 'overflow: hidden' property set on the unexpanded
message. Reset that property by adding 'overflow: initial' on the expanded
class.

Additionally, slightly enlarge the margin of the expanded message box.

giticon.png: use repotag class to make an icon

A quick search revealed that some old css code was never used, so it was
removed.

hgicon.png: use repotag class to make an icon

The inline 'style' attribute was modified to remove the color but nothing else,
as was discussed with other Kallithea devs, since it makes more sense to leave
the spacing until another pass of css refactoring.

A quick search revealed that some old css code was never used, so it was
removed.

pullrequests: allow closing only by author and admin

A pullrequest should not be closable by any reviewer, especially not since
there is no reopening feature.

The check on change_status is no longer necessary, as the new permission
check is more restrictive.

repository 'latest changes': only show first line of commit message

Instead of truncating the commit message at a fixed number of characters,
behave like standard version control commands (e.g. hg log) and only show
the first line of the commit message in an overview.