Compatibility with Vaadin 7.0.0.rc2
Do not make an RPC if the popup button is disabled, the server will
print warning messages and ignore the call
Merge pull request #5 from ingokegel/2.0

Compatibility with Vaadin 7.0.0.rc2
PopupButton is now a SingleComponentContainer
Correct versions for dependencies
Renamed Root -> UI
call setOwner for VOverlay
Cleaned up server-side API
PopupButton 2.2.0