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
echo "invalid" > .hg/hgrc
hg status 2>&1 |sed -e "s:/.*\(/t/.*\):...\1:"