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
#
hg init t
cd t
echo 1 > foo
hg ci -Am m
cd ..
hg clone t tt
cd tt
echo 1.1 > foo
hg ci -Am m
cd ../t
echo 1.2 > foo
hg ci -Am m
echo % should fail
hg pull -u ../tt
cd ../tt
echo % should fail
hg pull -u ../t
HGMERGE=true hg merge
hg ci -mm
cd ../t
echo % should work
hg pull -u ../tt