predict correctly
map errno in a different map

This way we can reference it from _lwp.c
integrate with rumpfiber scheduler
fix thread lookup (i.e. fix the whole park/unpark thing)
support timed sleeps
Merge branch 'lwp-rumpfiber' of github.com:rumpkernel/rumprun into lwp-rumpfiber

Conflicts:
	_lwp.c