git --diff: fix traceback when getting mode change - use the manifest instead of the mode in the working dir if the diff is against two revisions - add a testcase

#!/bin/sh

unset HGUSER
EMAIL="My Name <myname@example.com>"
export EMAIL

hg init test
cd test
touch asdf
hg add asdf
hg commit -d '1000000 0' -m commit-1
hg tip