Cyrus SASL 2 fixes for MySQL

[Bruce M Simpson]

Hi all,

I have been trying to get SMTP AUTH working in a hosting setup which I manage.
Tonight I succeeded.  In the course of so doing I've come up with a few
patches which seem to work well for me.

Please see: http://people.freebsd.org/~bms/cyrus-sasl-improvements.diff

The features are: improved debugging messages, optional use of an SSL
transport, and the ability to use MD5 hashes with MySQL or other auxprop
plugins.

Credit is due to Branko GrÄnar <bfg at noviforum.si> for the last two features.
I have tidied there to make a cleaner diff for 2.1.15.

At the moment this is a diff which can be applied to the cyrus-sasl2 port.
If there's further interest I'll roll the patches into the port itself with
toggle switches.

BMS