ecore-x-vsync - rearragnge to move vsync event input to thread

ecore-x-vsync - rearragnge to move vsync event input to thread

this uses a thread to collect vsync input events and filter them
before forwarding them to the mainloop (as a double timestamp). this
means wakeups only happen for the actual vsync and thus animator and
not for other screens we are filtering out anyway. this should fix the
continual animator wakeups that happen if you have a dri/drm based
driver and > 1 screen.