Abuse edit works

Resolves issue: http://code.google.com/p/otwarchive/issues/detail?id=3458

Removed the check on :edit_tags and :update_tags which was explicitly keeping admins out. 

Added :edit_tags and :update_tags to be excepted from the 'check_ownership' method but INSTEAD had those two tags checked with the 'check_ownership_or_admin' method.