logging module -- better timestamp accuracy on Windows

[benhoyt]

> AFAIK, the Windows performance counter has long-term accuracy issues,
> so neither is perfect. Preferably we should have a timer with the long-
> term accuracy of time.time and the short-term accuracy of time.clock.

Thanks for the tip -- yes, I hadn't thought about that, but you're right, QueryPerformanceCounter (and hence time.clock) veers away from the system time, and it's non-trivial to fix. See also:

http://msdn.microsoft.com/en-us/magazine/cc163996.aspx

http://social.msdn.microsoft.com/forums/en-US/windowsgeneraldevelopmentissues/thread/a8b2c286-1133-4827-97be-61e27687ff5d

-Ben