Revision 957899

fix intermittent failure in JDBCNegativeQueueTest, sync store add and cursor add such that cursor is always in order w.r.t the store. Hense, when the cursor cache is exhausted, resuming from the store is just fine. Without the sync, moving from cache to store can result in duplicate messages, out of order messages and on occasion missing messages. disabling the cache resolved all of the above but kills performance. Syncing the sore add and cursor add is the correct solution, but it has an impact on concurrent transaction completion for a destination, paralell completion across destinations can still continue, so there is still some batching potential