def clear(owner=nil)
      if(owner.nil?)
        @actions.clear
        @new_actions.clear
      else
        @actions.each{|a| @actions.delete(a) if a.owner == owner}
      end
      wakeup if running?
    end
def clear(owner=nil)
      if(owner.nil?)
        @actions.clear
        @new_actions.clear
      else
        @actions.each{|a| @actions.delete(a) if a.owner == owner}
      end
      wakeup if running?
    end
owner:: owner actions to remove
 Clears timer of actions. If an owner is supplied
 only actions owned by owner will be removed