Fixed wrong widget hovering for multiple windows
Fixed wrong widget hovering for multiple windows

Previously buttons would show up as hovered if another widget was
being hovered in another window. This behavior is now fixed and
everything should work correctly now.

OpenMusicKontrollers/synthpod,OpenMusicKontrollers/synthpod,OpenMusicKontrollers/midi_matrix.lv2,OpenMusicKontrollers/midi_matrix.lv2,OpenMusicKontrollers/sherlock.lv2,OpenMusicKontrollers/moony.lv2,OpenMusicKontrollers/synthpod,OpenMusicKontrollers/synthpod,OpenMusicKontrollers/sherlock.lv2,OpenMusicKontrollers/moony.lv2,OpenMusicKontrollers/midi_matrix.lv2,OpenMusicKontrollers/patchmatrix,OpenMusicKontrollers/moony.lv2,OpenMusicKontrollers/midi_matrix.lv2,OpenMusicKontrollers/patchmatrix,OpenMusicKontrollers/patchmatrix,OpenMusicKontrollers/moony.lv2,OpenMusicKontrollers/sherlock.lv2,OpenMusicKontrollers/moony.lv2,OpenMusicKontrollers/patchmatrix,OpenMusicKontrollers/synthpod,OpenMusicKontrollers/moony.lv2,OpenMusicKontrollers/sherlock.lv2