topic: add the changelog argument to branchinfo()
47c03042cd1d in core added a changelog argument to revbranchcache.branchinfo()
and we wrap that function in topic extension. So let's add this optional
argument in topic extension too.
# utility to setup pythonpath to point into the tested repository
export SRCDIR=`dirname $TESTDIR`
if [ -n "$PYTHONPATH" ]; then
export HGTEST_ORIG_PYTHONPATH=$PYTHONPATH
export PYTHONPATH=$SRCDIR:$PYTHONPATH
else
export PYTHONPATH=$SRCDIR
fi