SHA-2/512 is faster than 256 on 64-bit machines.
Whoops: Call Mailer::prepareToSend/sendPrepared correctly.

Previous code worked but was surprising.
Internal: Don't use preg_match unnecessarily.
Fix Contact::canViewDiscussionLead.

Within the class Contact::cid doesn't work!
Remove unused function.
Internal: Refer to the global $Me, not the session variable.

Principle of least surprise.
Introduce password reset link capability.

If the password is stored in plaintext, we still email it to you
in plaintext. But if it's stored as a hash, we email you a reset
link.

With this safePasswords is now usable by conferences.

Signed-off-by: Eddie Kohler <ekohler@gmail.com>
Return JSON on Ajax requests even if conference dead.
Default to safe passwords.

And Code/createdb.sh generates a random HMAC key.

Signed-off-by: Eddie Kohler <ekohler@gmail.com>