tests: add more testing of pulling with various setting
We checks for client/server with various combination:
* extensions enabled,
* extensions enabled but exchange disabled,
* extensions disabled,
# 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