When fps cap is hit, delay current thread only.

Fixes Jeanne d'Arc freezing.  Unfortunately, small hit to perf in God of
War, but may improve audio quality anyway...
Log context switch time, shorten logging a bit.

This is really useful for seeing why games are slow or hanging.
Merge pull request #3394 from unknownbrackets/framebuf-wait

Use a wait when hitting capped fps, instead of eating