docs/usage: rework and rename section 'Visual settings in admin pannel'

- remove trivial items that are already explained on the settings page
itself
- rename section to reflect this new scope
- general rewording

docs: update the translation howto

* Reformat to RST
* Add sections about using Weblate

i18n: updated translation for Dutch (Belgium)

Currently translated at 0.8% (9 of 1077 strings)

i18n: updated translation for German

Currently translated at 47.5% (512 of 1077 strings)

i18n: updated translation for Slovak

Currently translated at 3.8% (41 of 1077 strings)

javascript: use jQuery $.post instead of YAHOO.util.Connect.asyncRequest

ajaxPOST will add the extra custom X-PARTIAL-XHR header ... but it does no harm
in these cases.

setup: constrain dulwich to version 0.9.9

65c5e70a1d0c bumped the version to 0.10 but there seems to be some unicode
compatibility issues there. So for now, just stay on 0.9.9 which both works and
has the fix for CVE-2015-0838.

repo: remove old ez_setup.py

The purpose of this script was to download and install easy_install... which is
years past its expiration date. Instead, let's revamp and recommend newer tools
in the docs and start by removing this file.

style: remove css star hack for internet explorer 7

This is invalid css and only works on decrepit browsers. Remove it.

style: stop supporting internet explorer 6-8 gradients

This 'progid:' line was non-standard and is no longer needed for modern
browsers, including Internet Explorer > 9. Besides, all it did was add a
gradient, so not really that much of a loss for someone using an decrepit
browser.

controllers: consistently use formfill.render with force_defaults=False

The inconsistency could cause confusion for developers. It seems to me like
force_defaults=False should be the default ... and apparently it was that in
older versions of formfill.

It could perhaps make sense for us to have a wrapper that added the defualt
values once, instead of repeating it all over ;-)

pullrequests: saving raw_id instead of branch in org_ref

This fixes an issue when the pull request is created while the top commit
included is not the tip. In that case, the faulty code would but
branch:default:default as org_ref, that causes the pull request view to show
all commits on that branch instead of the wanted commit(s) only. The fix will
result in a branch:default:1234567890abcdef1234567890abcdef (e.g)

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.