Removed dependency on Geronimo TransactionContextManager

[Dain Sundstrom]

One of the biggest problem with using the OpenEJB 2 containers in 3  
is the extensive use of Geronimo's TransactionContextManager class to  
track transaction related data and to demarc transaction boundaries.   
I have just committed the necessary changes to remove this  
dependency.  We are now managing our own transaction data in the  
EjbTransactionContext object (note this is different from the 1  
TransactionContext class), and transaction demarcation is handled by  
directly manipulating the transaction manager.   I'd like to drop the  
transaction policy code from the 2 tree entierly and simply convert  
the 1 transaction code to an javax.interceptor.Interceptor  
implementation, but that is for another thread.

Anyways, we are one big step closer merged the 1 and 2 code bases :)
-dain