WL#437: MySQL should support Zeroconf/Bonjour

Use an existing library (e.g. mdnsd, avahi) to start an additional thread upon
startup that handles messaging.  

This feature should:
 -be a compile time option or plugin
 -allow the user to enable and disable it via a my.cnf


Bonjour aka Rendezvous enables automatic discovery of computers, devices, and
services on IP networks. Also known as Zero Configuration networking or
Zeroconf, Bonjour uses industry standard IP protocols to allow devices to
automatically find each other without the need to enter IP addresses or
configure DNS servers.
Bonjour is an open protocol, which Apple has submitted to the IETF as part of
the ongoing standards-creation process.

We should try to find out, if MySQL could be able to make use of this technology
so a MySQL server could automatically announce itself in a network. This concept
is not Mac OS X only, many platforms support it.

More information:

http://developer.apple.com/networking/bonjour/index.html
http://files.dns-sd.org/draft-cheshire-dnsext-nias.txt
http://krow.livejournal.com/492948.html
http://hg.tangent.org/mysql_zeroconf