output of 'make-tarball' now is tarball with name formatted as:
cloud-init-$VERSION~bzr$REVNO.tar.gz
Instead of
cloud-init-$VERSION-$REVNO.tar.gz
The former is desireable for apt at least as the '~' is understood
to mean less than.
This merges revno 569 and 570 from lp:~harlowja/cloud-init/rework