Added note when issue status changed (closed / reopened)

This reverts commit a25a85b9.

This reverts commit 78d88262.

Implementation is correctly done through observer.

Autolinks to issues in commit message (see #155)

Minor tweak to readme

Hide admin menu for non-admins

Conflicts:
	app/models/project.rb
	config/routes.rb
	db/schema.rb

I have to domesticate RubyMine, keymapping is not the same as IntelliJ and I have deleted a character by mistake...

2/ @commit.safe_message as an argument
3/ preserve in helper
4/ spaces around operators

It matches #[0-9]+ in commit messages.
For example
 * Fix for #12
 * Code review for #56
 * Test for #15, Review on #54, Fix for #42

 It only links to valid issues (existing and belonging to the current project)
 It does not add any link to the commit in the issue page, it only consists in parsing the commit message when displayed.

 This can be considere as a primary work for the issue #155 on gitlabhq/gitlabhq.