simplify make_filename, fix hg cat bug hg cat was using file-level rev/node ids for generating filename templates. This simplifies make_filename to only use changeset rev/node ids.

#!/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