Problematic Xid comparison in ActiveMQXASession

In ActiveMQXASession.java, Xids are tested for equality in various places using the == operator. This will not work properly if the Xids are equal but happen to be different objects. A better approach would be to use a boolean equals(Xid a, Xid b) method that tests the formatId, globalTransactionId and branchQualifier of the involved Xids for equality.