Code reviewed by: TopLink Team
Short Description: Added and implemented new extended property 'toplink.transaction.join-existing' to force persistence context to read through JTA-managed ("write") connection in case there is an active transaction, the default value for this property is false which means not using JTA-managed ("write") connection.
Test: Tested with entity-persistence-tests. New test cases have been created and attached in here and did not check in CVS since they are required to run on application server.