Bugzilla: support updating of bugs

- fhbz can now replace check-bz-available-URM
- update to use f22 cblrepo
- bugzillaQuery and bugzillaModify
- assume whiteboard format is just ^pkg-ver:STATE now($) now
- exclude ghc and git-annex (cblrepo heavy)

Utils: add cmdN for dry run of cmd_