Add branchtags function with cache - cache stores tipmost node and rev and node,label pairs - if cache is out of date, scan new changesets - write new cache out after scan

#!/bin/sh

echo 'syntax error' > badext.py
abspath=`pwd`/badext.py

echo '[extensions]' >> $HGRCPATH
echo "badext = $abspath" >> $HGRCPATH

hg -q help help