Rewrite and improve git backend logic. Fix project movind. Raise exception to prevent unexpected issues

When projects were created in projects_controller
create.js.haml passed notice as url parameter and
therefore notice was not displayed in the page after
redirect to the project page

Project -> update repo only on create and destroy. Fixtures Updated with namespaces. Fixed moving repo

Replaces two calls that this method simplifies

Didn't bother with files in db/, config/, or features/

see edd81a79

Project - restyled show page, removed info page
Repository - restyled show page, added download option
Tags - added download options

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