Simplify controllers and layout handling

changed the post-receive hook in order to push the correct repository 

models cleanup

Conflicts:
	app/controllers/commits_controller.rb
	app/controllers/refs_controller.rb

http://guides.rubyonrails.org/security.html#regular-expressions

Now it's consistent across layouts where their main menus are.

Also remove now-unused tab_class helper

Simplifies the actions in RepositoriesController

Closes #1452