Feature/gitlab-support

This commit adds support for GitLab notifications (push webhooks) available at
the url endpoint: '/hooks/gitlab/'.

Summary of the changes:
* Add the url endpoint and the appropriate gitlab handler method.
* Add to 'Notification hooks' on data/<project>.
* Add tests.
* Update documentation.

This commit has been tested with GitLab CE 7.1.0.

Fixes #498
Signed-off-by: Michal Čihař <michal@cihar.com>

Extract everything after refs/heads/ as branch.

By dropping the front part of the ref, one is able to use branches with deeper
nesting than 1. Since the subproject configuration allows this, it should be
supported by the github helper method.

Example ref spec:
* master
* foo/bar
* foo/bar/baz

For documentation, see (Payload -> ref) at
https://developer.github.com/v3/activity/events/types/#pushevent

Signed-off-by: Michal Čihař <michal@cihar.com>

Signed-off-by: Michal Čihař <michal@cihar.com>

Signed-off-by: Michal Čihař <michal@cihar.com>

Fix 'Title underline too short.' in documentation.

Signed-off-by: Michal Čihař <michal@cihar.com>

Mention a dependency to libfreetype6.

Libfreetype6 is essentially a dependency to compile Pillow with
libfreetype support. Without this library, the activity graphs are
broken and the following traceback appears in the logs:
  Traceback (most recent call last):
    File "/var/www/weblate-venv/local/lib/python2.7/site-packages/django/core/handlers/base.py", line 112, in get_response
      response = wrapped_callback(request, *callback_args, **callback_kwargs)
    File "/var/www/weblate/weblate/trans/views/charts.py", line 122, in monthly_activity
      return render_activity(activity)
    File "/var/www/weblate/weblate/trans/views/charts.py", line 52, in render_activity
      font = get_font(11)
    File "/var/www/weblate/weblate/trans/fonts.py", line 695, in get_font
      size
    File "/var/www/weblate-venv/local/lib/python2.7/site-packages/PIL/ImageFont.py", line 228, in truetype
      return FreeTypeFont(font, size, index, encoding)
    File "/var/www/weblate-venv/local/lib/python2.7/site-packages/PIL/ImageFont.py", line 131, in __init__
      self.font = core.getfont(font, size, index, encoding)
    File "/var/www/weblate-venv/local/lib/python2.7/site-packages/PIL/ImageFont.py", line 42, in __getattr__
      raise ImportError("The _imagingft C module is not installed")
  ImportError: The _imagingft C module is not installed

Signed-off-by: Michal Čihař <michal@cihar.com>

Signed-off-by: Michal Čihař <michal@cihar.com>

Signed-off-by: Michal Čihař <michal@cihar.com>

Signed-off-by: Michal Čihař <michal@cihar.com>

Signed-off-by: Michal Čihař <michal@cihar.com>

Currently translated at 93.9% (941 of 1002)

Currently translated at 100.0% (1002 of 1002)

Currently translated at 99.1% (993 of 1002)

Currently translated at 93.9% (941 of 1002)

Signed-off-by: Michal Čihař <michal@cihar.com>

Signed-off-by: Michal Čihař <michal@cihar.com>

Currently translated at 100.0% (1002 of 1002)

Signed-off-by: Michal Čihař <michal@cihar.com>

Signed-off-by: Michal Čihař <michal@cihar.com>

This way we offer only valid choices in the interface.

See also issue #491
Signed-off-by: Michal Čihař <michal@cihar.com>

Signed-off-by: Michal Čihař <michal@cihar.com>

Signed-off-by: Michal Čihař <michal@cihar.com>

Signed-off-by: Michal Čihař <michal@cihar.com>

Currently translated at 100.0% (1002 of 1002)

This needs https://github.com/translate/translate/pull/132 to work.

Fixes #491
Signed-off-by: Michal Čihař <michal@cihar.com>

Signed-off-by: Michal Čihař <michal@cihar.com>