Online registration now sends email. The confirmation URL doesn't

Online registration now sends email.  The confirmation URL doesn't
work yet.  The mail comes from mail_sender which MUST be configured.

sendmail() sends mail via the SMTP server specified in the config
file.  The default is localhost.  inputline() is extended to cope with
CRLF-flavored protocols.

local_hostname() returns the FQDN of the local host (assuming you
didn't screw up your /etc/hosts).

mime_encode_text() and mime_to_qp() prepare text/* messages for
sending in mail.