Revive commands.dispatch as a simple way to call hg from other pythons scripts. This was already used by hg-ssh and others and is really convenient if you just want a native equivalent of calling the command line version.

#!/bin/sh

hg init
python -c 'print "confuse str.splitlines\nembedded\rnewline"' > a
hg ci -Ama -d '1 0'
echo clean diff >> a
hg ci -mb -d '2 0'
hg diff -r0 -r1