Play optimizations

- Fix locking in Play classloader
https://github.com/playframework/play1/commit/63e5fbce6bec455b851f9214133916e6b6463d67
http://play.lighthouseapp.com/projects/57987/tickets/1459-blocked-threads-in-applicationclassloader
- JPABase.saveAndCascade will cache annotations
this is what `assert' is for