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
echo a > a
hg ci -d '0 0' -Ama
hg an a
HGRCPATH=$HGTMP/.hgrc; export HGRCPATH
echo "[ui]" >> $HGTMP/.hgrc
echo "strict=True" >> $HGTMP/.hgrc
hg an a
hg annotate a
echo % should succeed - up is an alias, not an abbreviation
hg up