Project activities perfomance increased. Cache for project activitites disabled. Repository conception changed

Delete .directory files

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...