bug#10294: 24.0.92; doc string of `set-face-attribute'

[Drew Adams]

The Elisp manual is clear.  The doc string is not:
 
 "FRAME nil means change attributes on all frames."
 
You must tell users just what "all frames" you have in mind here - be
explicit.  Say what the manual says:
 
 "this function sets the attributes for all existing frames, and the
  default for new frames"
 
It is quite important that by "all frames" you mean all existing frames
AND all future frames.  That is not clear, not obvious.
 
In GNU Emacs 24.0.92.1 (i386-mingw-nt5.1.2600) of 2011-12-06 on MARVIN
 Windowing system distributor `Microsoft Corp.', version 5.1.2600
 configured using `configure --with-gcc (4.6) --no-opt --cflags
 -ID:/devel/emacs/libs/libXpm-3.5.8/include
 -ID:/devel/emacs/libs/libXpm-3.5.8/src
 -ID:/devel/emacs/libs/libpng-dev_1.4.3-1/include
 -ID:/devel/emacs/libs/zlib-dev_1.2.5-2/include
 -ID:/devel/emacs/libs/giflib-4.1.4-1/include
 -ID:/devel/emacs/libs/jpeg-6b-4/include
 -ID:/devel/emacs/libs/tiff-3.8.2-1/include
 -ID:/devel/emacs/libs/gnutls-2.10.1/include --ldflags
 -LD:/devel/emacs/libs/gnutls-2.10.1/lib'