Implement IP pool-based automatic IP allocation support (OMS-264)
Fixes for bugs discovered while testing the new IP allocation feature (OMS-264)
Using Compute instances as dict keys was not a good idea after all (OMS-264)
Various fixes to IPv4Pool functionality (OMS-246)

Fixed MigrateAction, DeployAction
ComputeAction locking bug (would never unlock, action from action calls dead-lock)
Using netaddr.IPAddress instead of own class + wrapper class to facilitate DB storage
Improved IP allocation
Merge pull request #43 from opennode/oms-264

IPPool implementation (OMS-264)