toggle: change timeline direction even if playing already
toggle: change timeline direction even if playing already

If this is not done, the toggle visual state will not match actual state
after toggled twice quickly.

clutter-project/mx,jonnylamb/mx,clutter-project/mx,pwithnall/mx,jonnylamb/mx,pwithnall/mx,jonnylamb/mx,pwithnall/mx,pwithnall/mx,clutter-project/mx,jonnylamb/mx,clutter-project/mx