Debugging keyboard overlay+xbindkeys

[wettstae at gmail.com]

> - press caps
> - press f
> - release caps
> - wait
> - release f

In xserver/xkb/xkbPrKeyEv.c, there is a bug that prevents key
press/release to be tracked properly for keys with overlays, in case
such a key is down while the overlay state changes.  There is even a
comment (from 9/11/94) that mentions the problem.

Andreas