* Render right layout depends on current_user
* show sample git username/email when repo is empty
* Show extra info when browsing public area
* Fixed some tests related to public projects
* show comments in read-only for public projects
* Remove old public routing

* Show new merge request button from compare page
* Show message if user selected same branches
* Show message if compared branches are the same
* Prepend inputs with from/to labels

* added description
* simplified form
* enabled gfm autocomplete

Previously, only number of changed files mattered. Now, number of lines to render in the diff are also taken into account.

A hard limit is set, above which diffs are not rendered and users are not allowed to override that. This prevents high server
resource usage with huge commits.

Related to #1745, #2259

In addition, handle large commits for MergeRequests and Compare controllers.

Also fixes a bug where diffs are loaded twice, if user goes directly to merge_requests/:id/diffs URL.

Show permissions for all project.
Add ability to remove user from group if not an owner
Remove unnecessary admin controller