This patch add support for remote net consoles via udp similar to what 
you would do with a net console with u-boot or a linux kernel.  
Typically you use the netcat tool for this.

This patch also partially abstracts the ability to switch between the 
monitor and the main focus of a port.  I say it is only partially 
abstracted, because I only implemented the shared console support for 
the stdio and udp consoles.  To minimize the amount of changes in this 
patch, I left the stdio driver's stdio_clients array alone.  It seems 
that its main purpose was for monitor sharing, but I was not certain.  
If the only purpose was for the monitor, then the array can be 
refactored out in the future.

The code well on Win32 and Linux.  The original command line arguments 
and defaults were all preserved.  The new command line options were 
documented in the documentation section of the patch.

signed-off-by: jason.wessel@windriver.com

Jason.

PS:
I can also supply the netcat patches to force telnet into character mode 
with remote echo turned on.