small fixes for test-newbranch - hg tip doesn't use the branch cache; use hg log -r in its place - commit doesn't use a HG_MERGE environment variable - change the dates from "0 0" to "1000000 0"

#!/bin/sh

hg init a
echo a > a/a
hg --cwd a ci -A -m a
hg clone a b
echo b > b/b
hg --cwd b ci -A -m b
chmod 100 a/.hg
hg --cwd b push ../a
chmod 700 a/.hg