Bug ZK-2348: empty listheaders visibility problems when used along auxheaders
Merge branch 'master' of github.com:zkoss/zk
update test case
Bug ZK-2358: Column borders become mis-aligned to listbox header's border when scrolling to right-most position
Bug ZK-2356: Menu popup with onOpen event moving slightly when hovering
Merge pull request #79 from jerrywell/B70-ZK-2356

Bug ZK-2356: Menu popup with onOpen event moving slightly when hovering
Add server push debugging logger
WeakIdentityMap.keySet() should implement add() and addAll()
Merge branch 'master' of https://github.com/zkoss/zk