rem: WMSetRulerMoveAction(WMRuler *rPtr, WMAction *action, void *clientData)
add: void WMSetRulerMoveAction(WMRuler * rPtr, WMAction * action, void *clientData)
context: WMSetRulerMoveAction(WMRuler *rPtr, WMAction *action, void *clientData){    if(!rPtr)        return;    rPtr->moveAction = action;    rPtr->clientData = clientData;}