Update Functions chapter of Lisp manual; document closures.

* doc/emacs/functions.texi (What Is a Function): Add closures.  Mention
"return value" terminology.  Add xref for command-execute.  Remove
unused "keystroke command" terminology.
(Lambda Expressions): Give a different example than in the
following subsection.  Add xref to Anonymous Functions.
(Function Documentation): Remove gratuitous markup.
(Function Names): Move introductory text to `What Is a Function'.
(Defining Functions): Fix defun argument spec.
(Anonymous Functions): Document lambda macro explicitly.  Mention
effects on lexical binding.
(Function Cells): Downplay direct usage of fset.
(Closures): New node.
(Inline Functions): Remove "open-code" terminology.
(Declaring Functions): Minor tweak; .m is not C code.

* doc/emacs/variables.texi (Variables): Don't refer to "global value".
(Local Variables, Void Variables): Copyedits.
(Lexical Binding): Minor clarification of example.
(File Local Variables): Mention :safe and :risky defcustom args.
(Lexical Binding): Add xref to Closures node.

1 files changed, 4 insertions, 3 deletions

diff --git a/etc/NEWS b/etc/NEWS
index 6dc0756e880..0a401eb3a3f 100644
--- a/etc/NEWS
+++ b/etc/NEWS
@@ -1049,19 +1049,20 @@ sc.el, x-menu.el, rnews.el, rnewspost.el
 
 * Lisp changes in Emacs 24.1
 
++++
 ** Code can now use lexical scoping by default instead of dynamic scoping.
 The `lexical-binding' variable lets code use lexical scoping for local
 variables.  It is typically set via a file-local variable in the first
 line of the file, in which case it applies to all the code in that file.
-
++++
 *** `eval' takes a new optional argument `lexical' to choose the new lexical
 binding instead of the old dynamic binding mode.
-
++++
 *** Lexically scoped interpreted functions are represented with a new form
 of function value which looks like (closure ENV ARGS &rest BODY).
 
 *** New macro `letrec' to define recursive local functions.
-
++++
 *** New function `special-variable-p' to check whether a variable is
 declared as dynamically bound.