Yet another "think different" crap from Apple:

When setting window size (with method -setContentSize:), Cocoa actually MOVES
window (with some unearthly logic BTW), as it has origin in the left-bottom corner.
This seems to be a reason for a long living bug with dungling tooltips:
1. Open a menu (in a canvas) and try to select, say, "View"->"Status bar".
2. Menu (top-level window) takes a button grab (while button down).
3. When mouse button released, grab is cancelled, and a fake crossing event
   must be generated (menu is also closed at this moment) - pointer "jumps"
   from the grabbing window to some window which is actually under cursor.
4. This window is, say, TGedNameFrame - it creates a tooltip on a crossing event
   (enter notify).
5. Now f..g Cocoa MOVES the window, so TGedNameFrame NEVER receives leave notify event and
6. we have a dangling tooltip.