Fixed: window width was not constrained when platform window was resized.

Previously window heights were constrained to the usable screen when the platform window (virtual screen) resized, but widths were not. The code was there to constrain the width, but it wasn't being used.

This commit ensures the width constraining code is executed.

AppKit/CPWindow/CPWindow.j

@@ -3319,7 +3319,7 @@ var keyViewComparator = function(lhs, rhs, context)
     if (_autoresizingMask & CPWindowHeightSizable)
         newFrame.size.height += dY;
 
-    [self setFrame:newFrame];
+    [self _setFrame:newFrame display:YES animate:NO constrainWidth:YES constrainHeight:YES];
 }
 
 /*