Proposed changes:

	Use NSPR as an alternate thread runtime base like we do with GNU pth...
	Especially convenient with common use of nss for future tls.  Do we
	still keep GNU pth option if we do this?

	Use NSPR code base for simulating msw conditional variables for direct
	native msw threading if better than code we have in ucommon, or maybe
	use NSPR in place of native msw threading entirely?

	Add serialio class?

Rejected changes:

	DetachedThread delete this into dealloc() virtual...
		- use Thread::exit() virtual for this purpose instead


