New Zero-Configuration networking classes using Bonjour:

   - TBonjourRecord
   - TBonjourRegistrar
   - TBonjourBrowser
   - TBonjourResolver

Zeroconf is meant to solve the problem of finding services and connecting
to them. Instead of having to know a machine's IP address and port number
for the service, a machine offering a service simply announces that it
offers the service. Clients who want to use a service ask for all the
machines that are offering it and then the user decides which one to
connect to.

Traditionally, you would have to make sure that each machine is configured
correctly and on the network. Zeroconf takes care of all of this for you
for a local area network. Lots of new hardware, such as printers with
networking support or wireless routers, come with their own Zeroconf server
to allow easy network configuration. On Mac OS X, many applications take
advantage of Bonjour to advertise services, such as the ssh server,
iTunes shares, or iChat availability. Zeroconf is a powerful way of
simplifying your applications, and there are implementations available
for most operating systems.

If you have Mac OS X, you already have Bonjour installed; otherwise, you
can download the source code from the Apple website 
(http://developer.apple.com/Bonjour) and build and install Bonjour in
relatively short order. Most modern Linux distributions come with Avahi,
an LGPL implementation of Zeroconf with a compatibibility API for Bonjour.
The ROOT Bonjour classes were tested to work with both Apple's Bonjour
implementation and Avahi's Bonjour compatibility layer.

Service discovery consists of three steps: registering a service, browsing
for available services, and resolving the service to an actual address.
A server will register its services with the Bonjour daemon. Clients will
browse for services to get a list to provide to the user. Finally, when it
is time to connect to a service, the client will resolve the selected
service to an actual IP address and port and then connect to the service
provide using TCP/IP.


git-svn-id: http://root.cern.ch/svn/root/trunk@28781 27541ba8-7e3a-0410-8455-c3a389f83636