Finish the _remove_action method
Finish the _remove_action method

Actually remove the button from the dialog. Instead of just keeping the
MxAction around, maintain the relationship between action and button.

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