[RFC] Trying to fix desktop switches, cont.

[Rafał Mużyło]

So, after the previous post, I sat down and once again did some
thinking/tinkering.

Obviously, the previous patch couldn't work, at least not in the
restoring part.

This one seems to work (for now), though I've only did some very basic
testing.

It doesn't seem to be a way to add private data to a window, that would
both be only accessible by wine and integrated with standard winapi
calls. Correct me, if that's wrong.

While WS_HIDDEN would seem better fitting, AFAICT it removes the window
from event queues, so I went with WS_DISABLED. This time through
standard functions.