bug#9876: 24.0.90; doc for `define-derived-mode'

[Drew Adams]

The doc, in both the Elisp manual and the doc string, should say that
parameter NAME corresponds to variable `mode-name'.
 
Users who define major modes without using `define-derived-mode' will
learn about `mode-name' and understand it when they need it or come in
contact with it.  Users who use only `define-derived-mode' are ignorant
of this connection to the variable, unless the doc points it out.
 
Similarly, for other variables that might be concerned - e.g.,
`major-mode'.  Such variables should be mentioned in the doc for `d-d-m'
and the connection made to its parameters.
 
In GNU Emacs 24.0.90.1 (i386-mingw-nt5.1.2600)
 of 2011-10-24 on MARVIN
Windowing system distributor `Microsoft Corp.', version 5.1.2600
configured using `configure --with-gcc (4.6) --no-opt --cflags
-I"D:/devel/emacs/libs/libXpm-3.5.8/include"
-I"D:/devel/emacs/libs/libXpm-3.5.8/src"
-I"D:/devel/emacs/libs/libpng-dev_1.4.3-1/include"
-I"D:/devel/emacs/libs/zlib-dev_1.2.5-2/include"
-I"D:/devel/emacs/libs/giflib-4.1.4-1/include"
-I"D:/devel/emacs/libs/jpeg-6b-4/include"
-I"D:/devel/emacs/libs/tiff-3.8.2-1/include"
-I"D:/devel/emacs/libs/gnutls-2.10.1/include" --ldflags
-L"D:/devel/emacs/libs/gnutls-2.10.1/lib"'