High-precision timers on Windows

[Jan Holesovsky]

Hi Michael, Stephan, all,

I've re-implemented the Windows WinSalTimer using the Timer Queues to
get higher precision than ~15.6ms; please see

https://gerrit.libreoffice.org/#/c/11552/

With my testing, all seems to work as before, and even the parts that
need this high precision really get the events quickly :-)

Michael S. - does it fit your threading plans, please?

Checking / testing / feedback appreciated; I'll merge the change to
master on Tuesday, if there are no problems.

All the best,
Kendy