JBossCacheManager to handle tx exception gracefully

1. Currenly under endTransaction, we don't handle RollbackException directly. We need to do that such that the underlying tm can throw a RollbackException that causes the cache store to rollback. We don't need to anything about it if this were the case

2. processExpires uses batch transaction to process. But this should not be necessary since session expiration is a local mode anyway so it won't buy any speed up.