- add timeout when calling XCheckTypedWindowEvent
- fix broken IsClipboardFormatAvailable; it tried to do a trick with
  EnumClipboardFormats by making incorrect assumptions
- in X11DRV_IsClipboardFormatAvailable do a quick exit if no one owns
  the selection
- add 1 second *minimum* time lapse between XSelectionOwner calls
- sync clipboard ownership between different wine processes
- prevents apps from getting into wierd state where they thought they
  didn't own the selection but they did and as a result queried
  themselves for available selection data