Delete libraries obsolete since 23.1 and 23.2

Delete libraries obsolete since 23.1 and 23.2

Emacs 23.2 was released 10 years ago.  old-whitespace.el has a
replacement in whitespace.el and is no longer relevant.  The other
libraries implement compatibility with Lucid Emacs, a modified version
of Emacs last released in the 1990s.

* lisp/obsolete/ledit.el:
* lisp/obsolete/lmenu.el:
* lisp/obsolete/lucid.el:
* lisp/obsolete/old-whitespace.el: Delete files.  These libraries have
been obsolete since Emacs 23.1 or 23.2.
* etc/NEWS: Announce their deletion.

* admin/authors.el (authors-ignored-files)
(authors-fixed-entries, authors-valid-file-names):
* lisp/emulation/viper.el (viper-mode):
* lisp/ffap.el (ffap-menu-ask): Remove references to deleted files.