From Marcelo:

Tutorial on how to use TUdpSocket.
- udpserver.c is a small UDP echo server
- testTUdpSocket sends a message to the echo server and prints the answer


git-svn-id: http://root.cern.ch/svn/root/trunk@41633 27541ba8-7e3a-0410-8455-c3a389f83636