Remove some items obsolete since Emacs 22/23 from Gnus

Remove some items obsolete since Emacs 22/23 from Gnus

* lisp/gnus/gnus-art.el (gnus-article-hide-pgp-hook)
(gnus-treat-strip-pgp, gnus-treat-display-xface):
* lisp/gnus/gnus-msg.el (gnus-inews-mark-gcc-as-read):
* lisp/gnus/gnus-start.el (nnmail-spool-file):
* lisp/gnus/nnmail.el (nnmail-spool-file)
(nnmail-fix-eudora-headers): Remove items obsolete since 22.1.
* lisp/gnus/gnus-art.el (gnus-treat-display-x-face):
* lisp/gnus/gnus-msg.el (gnus-inews-do-gcc): Don't use above obsolete symbols.
* doc/misc/gnus.texi (Washing Mail, Not Reading Mail): Don't refer to
above obsolete variables.
; * etc/NEWS: List removed items.

* lisp/gnus/gnus.el (gnus-local-domain, gnus-carpal):
* lisp/gnus/nnimap.el (nnimap-split-rule):
* lisp/gnus/nntp.el (nntp-authinfo-file): Fix obsolete variable
version format.