Restricted access of the Resque Dashboard to admins only

Think I fixed the issue.  Added a controller.  Only other strange thing would be in routes.rb.  If the admin permission fails, it falls through and calls the default controller I created, which just checks the permission again with CanCan and displays the flash message like we discussed.

Hopefully this resolves enhancement #968 in Redmine.  There's a little more information in the write up there.