rio: handle greyscale fonts better
 [rsc] --rw-rw-r-- M 76409 glenda sys 33445 Mar 30 07:59 sys/src/cmd/rio/wind.c
	/n/sourcesdump/2006/0330/plan9/sys/src/cmd/rio/wind.c:709,716 - 
	/n/sourcesdump/2006/0331/plan9/sys/src/cmd/rio/wind.c:709,719
	  wrepaint(Window *w)
	  {
	  	wsetcols(w);
	- 	if(!w->mouseopen)
	+ 	if(!w->mouseopen){
	+ 		if(font->maxdepth > 1)
	+ 			draw(w->Frame.b, w->Frame.r, cols[BACK], nil, ZP);
	  		_frredraw(w, w->Frame.r.min);
	+ 	}
	  	if(w == input){
	  		wborder(w, Selborder);
	  		wsetcursor(w, 0);