This is the HEAD of the original OVM3 drop

Tagging release 4.3.0 on branch 4.3

Tagging release 4.2.1 on branch 4.2.

Tagging 4.2.0 release

Tagging release 4.1.1 on branch 4.1.

Tagging release 4.1.0 on branch 4.1.

Tagging release 4.0.2 on branch 4.0.

Tagging release 4.0.1-incubating on branch 4.0

Tagging release 4.0.0-incubating on branch 4.0.

Bug : 15133

      only delete snapshot which is not referenced by any snapshots in DB for a volume