This makes the receiver always send a full list of valid refs, which
will allow us to do better packs, as well as handle creation of new
refs. Eventually. Right now we just moved the matching and enabled it.
So now you can do
git-send-pack host:path branch1 branch2
to only send branches "branch1" and "branch2".
This concludes this lesson. I've actually successfully sent an update
using the git-send-pack command.
Probably tons of work still to do, and nasty debugging, but it's now
actually potentially useful.
