merge: pull user messages out to hg.py - add _update for shadowing in clone - add _showstats helper - remove update parameter defaults - move stats message and merge help messages

#!/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