bug#11040: 24.0.94; doc string of `indirect-variable'

[Drew Adams]

The doc string, unlike (elisp) `Variable Aliases', is not at all clear.
It says nothing about what is meant here by "indirection".  This is
Lisp.  There are several kinds of "indirection" for Lisp variables,
including via values and via properties.
 
The manual makes clear what is meant by talking about "aliases", which
is the kind of indirection this function is about.  Please do similarly
for the doc string.
 
To be even clearer, the doc (in both places, but especially the doc
string, since the manual node already sets the context) should
explicitly mention `defvaralias' when referring to variable aliasing.
 

In GNU Emacs 24.0.94.1 (i386-mingw-nt5.1.2600)
 of 2012-02-26 on MARVIN
Windowing system distributor `Microsoft Corp.', version 5.1.2600
Configured using:
 `configure --with-gcc (4.6) --no-opt --enable-checking --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-3.0.9/include'