JBRULES-3397, BZ 767502: Added local transaction support (LocalTransactionManager) and refactored persistence code to support it.

- a 'attachPersistenceContext(...)' method has been added to the drools TransactionManager and implemented for all implementations
- A separate commit will do this for the drools-integration (spring-based) transaction managers
JBRULES-3397, BZ 767502: Tests for local tx based persistence.

- New tests added.
- Existing tests modified to also test using local transaction based persistence.
- The RerunWithLocalTransactions is a Junit rule class that reruns tests
  that implement the VariablePersistence interface