Add ui.strict config item. This turns off command matching by unambiguous prefix, and is a good thing if you want to write future-proof scripts. This fixes issue 314.

#!/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