add --daemon option to serve command. for issue 45. code looks odd because it is portable to windows. windows does not have os.fork, so have to spawn and use pipe to tell parent ready instead.

#!/bin/sh

hg
hg -q
hg help
hg -q help
hg add -h
hg add --skjdfks
hg help diff
hg help status
hg -q help status
hg help foo
hg skjdfks

exit 0