Permission and User models updated.
Added Group model.
Load Group, Permission and User models.
Get current user if logged in, otherwise great a dummy guest user.
Check if the user has permission to view the project.
Stop that.
Added guest and 404 error translations.
Added 404 page view.
Added copyright and license block to Project and Setting models.
Set @current_project to false if the user doesn't have permission to view it.