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 repo
cd repo
echo foo > foo
hg ci -qAm 'add foo' -d '0 0'
echo >> foo
hg ci -m 'change foo' -d '0 0'
hg up -qC 0
echo bar > bar
hg ci -qAm 'add bar' -d '0 0'
hg log
cd ..
hg init copy
cd copy
echo '% pull -r 0'
hg pull -qr 0 ../repo
hg log
echo '% pull -r 1'
hg pull -qr 1 ../repo
hg log
# this used to abort: received changelog group is empty
echo '% pull -r 1 again'
hg pull -qr 1 ../repo