bug#22336: 25.0.50; cl-generic.el features are not documented in ELisp manual

[Eli Zaretskii]

It looks like the new features, implemented by cl-generic.el and used
quite a lot in our sources, are not documented in any manual.  Their doc
strings are impenetrable to anyone who isn't already familiar with CLOS
multiple-dispatch generics, as they use terminology ("specializers",
"generalizers", "dispatch", etc.) not explained anywhere.  NEWS has
this to say about them:

  ** cl-generic.el provides CLOS-style multiple-dispatch generic functions.

That's the entire text of the entry.  It diesn't even mention the 2
entry points, 'cl-defgeneric' and 'cl-defmethod'.

The generics should be prominently documented either in the ELisp
manual.  Emacs 25.1 should have them documented, due to their wide usage
in the core packages and elsewhere.



In GNU Emacs 25.0.50.281 (i686-pc-mingw32)
 of 2016-01-08 built on HOME-C4E4A596F7
Repository revision: 1a6b0846b5fbf08aa4288ae9e47c59cfca30459f
Windowing system distributor 'Microsoft Corp.', version 5.1.2600
Configured using:
 'configure --prefix=/d/usr --enable-checking=yes,glyphs --with-wide-int
 --with-modules 'CFLAGS=-O0 -gdwarf-4 -g3''

Configured features:
XPM JPEG TIFF GIF PNG RSVG SOUND NOTIFY ACL GNUTLS LIBXML2 ZLIB
TOOLKIT_SCROLL_BARS MODULES

Important settings:
  value of $LANG: ENU
  locale-coding-system: cp1255

Major mode: Lisp Interaction

Minor modes in effect:
  tooltip-mode: t
  global-eldoc-mode: t
  electric-indent-mode: t
  mouse-wheel-mode: t
  tool-bar-mode: t
  menu-bar-mode: t
  file-name-shadow-mode: t
  global-font-lock-mode: t
  font-lock-mode: t
  blink-cursor-mode: t
  auto-composition-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t
  line-number-mode: t
  transient-mark-mode: t

Recent messages:
For information about GNU Emacs and the GNU system, type C-h C-a.

Load-path shadows:
None found.

Features:
(shadow sort mail-extr emacsbug message dired format-spec rfc822 mml
mml-sec epg epg-config gnus-util mm-decode mm-bodies mm-encode
mail-parse rfc2231 mailabbrev gmm-utils mailheader sendmail rfc2047
rfc2045 ietf-drums mm-util help-fns help-mode easymenu cl-loaddefs pcase
cl-lib mail-prsvr mail-utils time-date mule-util tooltip eldoc electric
uniquify ediff-hook vc-hooks lisp-float-type mwheel dos-w32 ls-lisp
disp-table w32-win w32-vars term/common-win tool-bar dnd fontset image
regexp-opt fringe tabulated-list newcomment elisp-mode lisp-mode
prog-mode register page menu-bar rfn-eshadow timer select scroll-bar
mouse jit-lock font-lock syntax facemenu font-core frame cl-generic cham
georgian utf-8-lang misc-lang vietnamese tibetan thai tai-viet lao
korean japanese eucjp-ms cp51932 hebrew greek romanian slovak czech
european ethiopic indian cyrillic chinese charscript case-table epa-hook
jka-cmpr-hook help simple abbrev minibuffer cl-preloaded nadvice
loaddefs button faces cus-face macroexp files text-properties overlay
sha1 md5 base64 format env code-pages mule custom widget
hashtable-print-readable backquote w32notify w32 multi-tty
make-network-process emacs)

Memory information:
((conses 16 92854 5930)
 (symbols 56 20660 0)
 (miscs 48 36 107)
 (strings 16 17691 6375)
 (string-bytes 1 438680)
 (vectors 16 12303)
 (vector-slots 8 418992 3863)
 (floats 8 162 76)
 (intervals 40 261 118)
 (buffers 856 11))