Changes for buliding with firestack

More an RFC than a direct pull request, as I'm not 100% sure what to do here

Firestack creates a new source .tgz from git, thus "%setup ceilometer-%{version}.b1" fails because rpm thinks the source dir has .b1 appended to it, which it doesn't.  What's the correct way to handle this?

The other change is to update the included patch so it applies against current git.  I think this is appropriate for the master branch, which should track upstream?