windows asyncio woes

[hartytp]

CabbageDevelopment/qasync#22

[hartytp]

I spent a little time starting at the underlying OSError but pretty quickly gave up. Windows ICOP is messy. I suspect it's a race condition somewhere in asyncio (maybe related to https://bugs.python.org/issue34795) which could turn into a huge timesink.

AFACIT other than the qasync issue here, it should be pretty harmless other than annoying noise in the logs. So I don't think it's worth the time it would take to debug it further.

cf https://github.com/python/cpython/blob/f5e97b72fecff9b9ced35704ec5e6cad29e2825d/Lib/asyncio/proactor_events.py#L162

cc @dnadlinger