Clean up date and timezone handling.
We used to pass changelog dates around as a "unixtime timezone" string
containing a pair of encoded ints. Now, they get passed around as a
(unixtime, timezone) tuple of numbers, which makes much more sense.
#!/bin/sh
hg init
echo "[hooks]" > .hg/hgrc
echo 'precommit = echo precommit hook' >> .hg/hgrc
echo 'commit = echo commit hook: $NODE' >> .hg/hgrc
echo a > a
hg add a
hg commit -m "test" -d "0 0"