tests/test-issue612

Fix income/pull with bundle and -R (issue 820).

Uses ui.setconfig() to tell bundlerepo where the main repo is. This is
needed for when the --repository option is used.

Adds tests to test-bundle and a new test script
test-mq-pull-from-bundle, which plays out the situation that initially
made me detect this bug

(hg -R .hg/patches pull ../bundle.hg).

#!/bin/sh

mkdir t
cd t

hg init
mkdir src
echo a > src/a.c
hg ci -Ama -d "10000000 0"

hg mv src source
hg ci -Ammove -d "1000000 0"

hg co -C 0
echo new > src/a.c
echo compiled > src/a.o
hg ci -mupdate -d "1000000 0"

hg st

hg merge

hg st