relax reference clock monotonicity checks
relax reference clock monotonicity checks

On Windows, the only truly monotonic clock is the TSC these days. So we
have to make due with a crappy reference clock.

Signed-off-by: Steven Noonan <4068f0880b399410602d694b3cc711c8a8f4727e@uplinklabs.net>

tycho/clockperf,tycho/clockperf