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
touch a
hg add a
hg ci -m "a" -d "1000000 0"

echo 123 > b
hg add b
hg diff --nodates

hg diff --nodates -r tip

echo foo > a
hg diff --nodates