[RFA] Remote UDP support

[Andrew Cagney]

> I really disagree with this.  It's fine to print a one-line warning
> --- something that doesn't interrupt the user's train of thought.  But
> people aren't going to type "target remote udp:..." by accident.
> 
> Whenever I've said, "UDP isn't reliable!", nobody has ever reacted
> with shock --- "You're kidding!  It isn't?"  They always say, "Yes, I
> know, and I don't care."

I think there is a subtle difference between someone understanding that 
``UDP is unreliable'' and someone understanding that the remote protocol 
doesn't work across UDP.

Take for instance, TFTP.  Everyone knows that TFTP uses good old 
unreliable UDP but hey that still works, right?  It just means that it 
has the occasional hickup.

GDB's remote protocol can't come close to meeting even that expecation. 
  Drop a packet and the session can die.

BTW, anyone thought to try typing in ``tiny tcp stack'' in a search engine?

enjoy,
Andrew