ietf-nntp "Common NNTP Extensions" document updated

[Brian Kantor]

Since I too won't be at the meeting, I would just like to make the
point that it is possible (in fact, rather easy) to implement
'newnews' quite efficiently, and that the laziness of programmers
in implementing it is insufficient reason to deprecate the command.

If there is good reason for "newnews" to go away, it should, but
poor implementation in existing software is NOT a good reason.
	- Brian