prune: replace --biject with --pair People have been complaining about `--biject` being to obscure for a while. A recent discussion with Pulkit Goyal and Dan Villiom Podlaski Christiansen produce some new concrete proposal that we liked. We eventually settle on using `--pair`. The `--biject` flag will be kept as an alias for a while.

. $TESTDIR/testlib/pythonpath.sh

cat >> $HGRCPATH << EOF
[extensions]
docgraph=
EOF