1) Adds a DB migration for all services to toggle on push, issue, and merge events.

2) Upon an issue or merge request event, fire service hooks.

3) Slack service supports custom messages for each of these events. Other services
not supported at the moment.

4) Label merge request hooks with their corresponding actions.

Irker is a gateway which sends IRC messages on git updates. This new
service provides an interface to this gateway, integrated in Gitlab, for
each updates.
As per the guidelines, this commit adds the new feature in the
CHANGELOG, tests and documentation.

See http://www.catb.org/esr/irker/

* Impl Project#avatar_url
* Refactor ApplicationHelper: Use Project#avatar_url
* Update changelog

This reverts commit 7d5f86f6.

This commit moves the note folder from
/public/uploads/note
to
/uploads/note
and changes the uploader accordingly.
Now it's no longer possible to avoid the access control by modifing the url.
The Avatar upload has been refactored to use an own uploader as well
to cleanly seperate the two upload types.

Make the following changes to deal with new behavior in Rails 4.1.2:

* Use nested resources to avoid slashes in arguments to path helpers.

Because since project always belongs to namespace it dont need such
strict restrictions any more

Also add ability to render "service.help" in markdown

adding avatar to project settings page added avatar removal show project avatar on dashboard, projects page, project page added rspec and feature tests added project avatar from repository new default project icon added added copying af avatar to forking of project added generated icon fixed avatar fork hound fix style fix test fix