remove unused RA_IsOffscreen method
remove unused RA_FindWindowByPID
remove unused RA_GetDesktopHandle
remove unused Window#display_tree and Window#gather_children
remove commented out code in MsUia::Control
Merge branch 'uiadll-cleanup' of git://github.com/leviwilson/RAutomation into leviwilson-uiadll-cleanup
Merge branch 'master' of github.com:jarmo/RAutomation