Optimized commit diff views, now showing file size and file mode changes

Fix hooks for merge requests which were accepted by web-interface

Update Gems

Replaced commit status images (diff_file_*.png) with fontawesome icons

Fix editor

Add file line links

Use poltergeist instaead of capybara-webkit

Also fixes #1983

Remove backward compatibility of factories.

Ensure git can commit and prevent it from failing silently

Update thin closes #1765 and maybe #1051

Conflicts:
	doc/install/installation.md

Supported formats: "L12" for single lines and "L12-34" for multiple lines