Several usablity tweaks:
- Search menu allows ScrollWheel to view items
- Tooltip on button on bottom of window showed wrong
- Tooltips were popping up while draggin (MMB) or scrolling
(wheel). Now they stay away.
- Stolen from Gimp (blame venomgfx for hint!): ScrollWheel allows
to go over menu items and use number buttons, only on mouse-over.
Note for devs: the WM_event_add_mousemove() call (to add a fake
event to bring UI back alive after view changes) now works much
more reliably. It ensures the mouse move is only handled after all
notifiers/redraws were done.