tests/test-hup

fix util.canonpath on windows.
old test for absolute path was not portable. use os.path api instead.

#!/bin/sh

hg init
mkfifo p

hg serve --stdio < p &
P=$!
(echo lock; echo addchangegroup; sleep 5) > p &
Q=$!
sleep 1
kill -HUP $P
wait
ls .hg