#1332 Moving toplevel windows fails

[Heiko Schock]

Moving or resizing toplevel windows under Windows OS
sometimes fails. This problem occured within an
application running cyclic http calls. The attached
code reduces the problem to a few lines of code. To
reproduce the problem simply run the attached code
inside a wish, drag the window to another position and
wait until the mouse looses the window (still holding
the left mousebutton).

[Heiko Schock]

Background procedure with vwait