build: add explicit commit to rc1, rc2 builds, and add ".0" to post-non-dot-release...

build: add explicit commit to rc1, rc2 builds, and add ".0" to post-non-dot-release per-patch builds

This addresses problem with incorrect sorting of artifacts in the per-patch packagecloud repositories
for throttle branches, by slightly changing the version string for the non-released (per-build) artifacts:

1) the rc1 and rc2 artifacts now will have the count of
   commits since tag (0) and the explicit commit hash

2) the builds after version XX.YY but before XX.YY.1
are named as if the version was "XX.YY.0"

Type: fix
Change-Id: Ib69a59ee98aa296c5cb24b183bba807b6cb3c05c
Signed-off-by: Andrew Yourtchenko <ayourtch@gmail.com>