Adds support for both dovecot CRAM-MD5 authentication and ldap binding, by:
- enabling multiple ldap userPasswords (ldap does not support CRAM-MD5 bind, so it needs more than one). Backward-compatible: just add encodings in password_ldap_encodage separating with a plus (+).
- adding a helper by Hajo Noerenberg (dovecot) to generate the dovecot hmac md5 (see helpers/dovecot_hmacmd5.php)
- updated config documentation
Also corrects the handling of ssha passwords: if sha1 function is present, it will be preferred (as it outputs the correct password for ldap, whereas hash seems not).