If a timer is requested with <=100ms resolution, request the high-res
timer. Since the default Windows timer period is 15ms, this means a
100ms timer could fire at 115ms (15% late). We assume that timers longer
than 100ms are a reasonable cutoff here.
The high-res timers on Windows are still limited. Unfortuntely this
means that our shortest duration 4ms timers can still be 25% late, but
without a more complex timer system or spinning on the clock itself,
we're somewhat bounded by the OS' scheduler itself.
