Final versioning for 2012.2.3

Change-Id: Ic83a1c1617ad74b931f54f1755bc9dcecfe2c527
Bump version to 2012.2.4

Set version to 2012.2.4, but with final=False

Change-Id: I9dab1dc62e41cdb4143a3c8083e65c4b13a22eb4
Integrate nova-network into Piston networking model.