refix ZK-2294: Combobox popup scroll back to top when navigating by keyboard
Merge branch '6.5' of https://github.com/zkoss/zk into 6.5
Merge pull request #94 from jerrywell/6.5

refix ZK-2294: Combobox popup scroll back to top when navigating by k…
Merge remote-tracking branch 'upstream/6.5'