Moving https://wiki.php.net/rfc/password_registry to "Under
Discussion" (previously "Draft").
Since originally drafting this proposal, I've changed the algorithm
selector from the current integer set to a more predictable string key
(similar to the hash extension). I think I'll probably extend this
slightly further to overload the function algo parameters such that
they'll accept integer (0-3) as BC for DEFAULT, BCRYPT, ARGON2I, and
ARGON2ID respectively. Please comment if you think that's a bad idea
(or a good one).