ORBit2-Beginners doc update (v1.4)

[Frank Rehberger <Frank Rehberger web de>]

Hello,

due to frequent request in mailing list a new sample has been added to 
ORBit2-Beginners docs to demonstrate usage of ORBit2 for multi-threaded 
application.  Further on, all samples have been adapted to use 
multi-threaded setup as default "orbit-local-mt-orb".

In new sample "threaded-calculator" the CORBA ORB is going to be 
initialized as background task, responding to requests from clients; the 
main thread in foreground is doing nonsense, but concurrently. If main 
thread receives SIGINT or SIGHUP specific signal-handler "main_shutdown" 
propagates SIGTERM to all associated processes/threads in process group 
(useful for all linuces<=2.4), this will invoke "server_shutdown" to 
shutdown CORBA ORB in background.

The sample is using portable g_thread library to create/join threads.

Please have a look at:
http://www.gnome.org/projects/ORBit2/orbit-docs/orbit/book1.html

Comments are welcome.

Regards, Frank