The beginnings of a JPA datasync system. Everything is subject to change!
Added test for conflicting update response
Added test for pushing non-conflicting update

I had to change the date field in the entity to be of type Timestamp, because
java.util.Date.equals(java.util.Timestamp) is always false, and this was tricking
the state comparator.
Added more scenarios to cold sync requests and responses
Added ability to delete pre-existing entities in sync request
Added support for annotation-based global entity listener (gets all JPA lifecycle events for all entity types)
Refactored ErraiEntityManager and its generator to make it easier to create multiple instances.

Unfortunately, this caused me to introduce two new factory interfaces. Sorry about that. :-/

The motivation for this change is that I want to keep a second ErraiEntityManager around for
tracking the state we believe the server has for each entity reachable from a SyncableDataSet.
Implemented namespacing at the EntityManager and WebStorageBackend levels
Made the To-do list demo deployable on JBoss AS 7 with Bus & CDI communication working
Removed unused maven property
Removed unnecessary noise from web.xml (no effective change in deployment behaviour)
Excluding netty (both variants!) so the todo-list demo can deploy to JBoss AS
Improved error message for unmarshallable member of portable type
Refactored datasync so SyncableDataSet and all the sync operations are portable

Unfortunately, the unit tests need an equally big refactoring now, and this hasn't been completed yet.
Made the todo-list capable of performing a round-trip datasync exchange with the server-side sync service
All but 2 of the new EntityManager.merge() tests are passing now.
Made the cascading merge test pass. Now to work on merging across plural attributes...
Fixed so null-valued collection attributes don't cause NPE during merge
Made cascading merge pass JPA rules 1-4 inclusive (tests for 5 and 6 still pending)
Renamed a few things after a quick walkthrough/review with csadilek