changelog: don't select all checkboxes in the middle

The changesets in the log might not be linearly connected and intermediate
changesets might not be a part of the operation the range is used for.

Some way of highlighting the two selected changesets and some radio button
functionality would however be nice.

"Users groups" is grammatically incorrect English - rename to "user groups"

- and same story with "repositories groups"

This will only change the user facing texts. Names of files, modules, functions
and variables should be changed too.

moved out password reset tasks from celery, it doesn't make any sense to keep them there, additionally they are broken
in when executing _(), and url() calls. This fixes issue #572

--version command should be safe, and bare no modifications
- improved subprocess calls error detection
- fixed I/O read on closed file errors

implemented #689 Deleting Repositories with Forks Should Be Easier
- optionally detach or delete forks associated to repo

review members are dynamically changed based on selected other_repo owner
- implemented pyroutes for smarter JS url handling
- fixed some old style global var routing

revision extraction function shouldn't be so eager, just extract commits that are
surrounded with spaces, or they are at beginning of the whole string
- wrote tests for that
- used parametrized for other tests

cleanup would recurse into every leaf and could thus not be used on lots of
large repositories.

fixed pull-requests with cherry picking changesets
- fixed tests for them

move permission check of write access to repo groups inside a form.
- it's runned via create/edit/fork forms
- in case we have disabled repo creation, it will check root location write access for people that are not super admins, or have explicity create repo permission
- in case there's a group value passed to form, it checks just admin or write access

fixes #762, LDAP and container created users are now activated based on
the registration settings in permissions

make the htsts headers optional and stored in .ini file.
also don't use it with DEBUG

fixes issue #756 cleanup repos didn't properly compose paths of repos to be cleaned up.
- it just worked on repos on root filesystem

git hook handler shouldn't ever use cache instances
- moved cache invalidation into finally block so we invalidate at latest possible stage
- added scm_instance_no_cache property to get non cached scm instances always

reposcann should skip directories with starting with '.'
some code cleanup, moved all skipping to get_repos function

fixes for issue #731, update-repoinfo sometimes failed to update data when changesets
were initial commits

improved extraction of user from changeset when sending notification.
Fallback to repo owner if we cannot get the user

unified RhodeCode paster commands
- moved them to commont paster_commands package
- re-use sqlalchemy session initializaiton
- some docs updates

fixes #753 inform about some problems with antivirus software in RhodeCode
on windows

fixes issue #756 cleanup repos didn't properly compose paths of repos to be cleaned up.
- it just worked on repos on root filesystem

Implemented #738 Giving a user WRITE+ permissions on folder should not allow repo creation in root folder.
user can create repos only if he got explicitly permission for creating repos globally, or have WRITE+ permission on a group.
Then he can create repositories inside this group

pull request: update changeset list automatically - remove refresh icon

With most of the UI giving immediate response it was confusing that we had to
press 'refresh' manually'. The icon could also be misunderstood as a 'swap'
symbol or as reload/reset.

compare: show aggregated diff of what will be merged to other repo, using merge ancestor

pull_request.get_compare_data will also now return the ancestor that would be
used for actual merging. Showing a diff from that ancestor instead of the first
'new' changeset will give a more realistic diff that doesn't include merges.

compare: swap org and other when they refer to different repos, ie are pull request style

Pull requests will have a different from/to description - but in a consistent
and slightly better way that can be improved later.

A pull request diff is empathic: "How will this look for the peer I'm proposing to" style.

compare: rename optional compare_url parameter repo to other_repo

At the same time it is placed before other_ref_type and other_ref. Just to keep
a logical flow and (a new) consistency that will help the next refactoring.