Bug fixed B65-ZK-1847: When sending a request without data to server,
the created event's data is an empty map instead of null
http://tracker.zkoss.org/browse/ZK-1847
revise comment
FIX ZK-1777: Server Push does not initialize when recycling
Merge branch 'ZK-B65-1847' of git://github.com/RaymondChao/zk
Merge branch 'B65-ZK-1777' of git://github.com/cor3000/zk