Implement scrollbars

- They work almost as you'd expect, though holding the mouse down on an arrow only scrolls once, and it's a little jerky
- Add an additional refresh option to redraw_screen, currently only partially implemented
- Scrollbars now have a page size in addition to pos and max
- cControl::handleClick() now takes the location clicked as a parameter, though the default implementation doesn't use it
- cControl::handleClick() is no longer responsible for redrawing the control when there is no parent dialog
- Fix cTextMsg not allowing retrieval of frame style

osx/dialogxml/message.cpp

@@ -61,6 +61,8 @@ short cTextMsg::getFormat(eFormat prop) throw(xUnsupportedProp){
 	switch(prop){
 		case TXT_FRAME:
 			return drawFramed;
+		case TXT_FRAMESTYLE:
+			return frameStyle;
 		case TXT_SIZE:
 			return textSize;
 		case TXT_FONT: