bug#14199: 24.3.50; `read-kbd-macro' doc

[Drew Adams]

In (elisp) `Describing Characters', description of `read-kbd-macro':
 
1. The signature and description are incorrect/incomplete.  According to
the source code and the doc string, the signature is (read-kbd-macro
START &optional END).
 
The doc string shows the correct signature, and it is clearer than
the manual wrt the signature and the possibility of passing STRING
and NEED-VECTOR instead.
 
The manual needs to clearly point out that there are, in effect, two
different signatures, even if one is considered primary.  Each needs
to be documented.
 
So do not remove the existing description about STRING and NEED-VECTOR.
Instead, supplement it with a description of the other signature and its
behavior.
 
2. Mention that STRING has the form provided by `format-kbd-macro'.
`format-kbd-macro' is mentioned nowhere in the manual, and this is a
good place for it.
 
In GNU Emacs 24.3.50.1 (i386-mingw-nt5.1.2600)
 of 2013-04-09 on ODIEONE
Bzr revision: 112253 rgm@gnu.org-20130409101736-f1vzgrwt88suqqis
Windowing system distributor `Microsoft Corp.', version 5.1.2600
Configured using:
 `configure --with-gcc (4.7) --no-opt --enable-checking --cflags
 -IC:/Devel/emacs/build/include --ldflags -LC:/Devel/emacs/build/lib'