Drag continues after drag/drop operation, until next mouse click (OS X)

[dakcarto]

On OS X, moving the cursor around after a drag/drop operation (tested with GeoServer items, may be others) acts as if the mouse button is still pressed, i.e. the button release to initiate the drop does not finish the button release event.

Guess on a fix: probably just need to pass the interrupted event on to the parent class.