return true/false on success of child add/remove
return true/false on success of child add/remove

arshaw/fullcalendar,fullcalendar/fullcalendar,oleg-babintsev/fullcalendar,arshaw/fullcalendar,arshaw/fullcalendar,kleisauke/fullcalendar,fullcalendar/fullcalendar,kleisauke/fullcalendar,fullcalendar/fullcalendar,kleisauke/fullcalendar,arshaw/fullcalendar,fullcalendar/fullcalendar,kleisauke/fullcalendar,oleg-babintsev/fullcalendar,oleg-babintsev/fullcalendar