revlog: use the new Config classes in _testrevlog
the mock object need to follow the new interface. We allow ourself a small
hacky import since this is testing code.
The legacy attribute are still here because some code still use them. We will
drop them when this code is updated.
$ echo "[extensions]" >> $HGRCPATH
$ echo "mq=" >> $HGRCPATH
$ hg init repo
$ cd repo
$ echo 'base' > base
$ hg ci -Ambase
adding base
$ hg qnew -mmqbase mqbase
$ hg qsave
$ hg qrestore 2
restoring status: hg patches saved state