[kbswitch] handle mouse events same as MS does PATCH

currently kbswitch systray icon reacts to MOUSE_BUTTON_DOWN

This does not feel natural and is not same as MS does.

E.g: The current way implies, that you could left-click-n-hold, choose your layout and then release. but this does not work.

It's better to do the same as MS and use MOUSE_BUTTON_UP instead.
Feels more natural and is also more compatible.

patch is tested and works on ROS and winXP.

Full name:Joachim Henze
make-kbswitch-feel-more-like-win-counterpart-mousewise.patch
Can anyone commit?

Btw: kbswitch (and others?) suffer from another serious issue
which is not related to this patch in any way:
https://jira.reactos.org/browse/CORE-9884