fix documentation for option-set! syntaxen

* doc/ref/api-evaluation.texi (Scheme Read): Note that read-set! is
  syntax.
  (Scheme Write): Likewise for print-set!.

* doc/ref/api-io.texi (Writing): Remove reference to
  print-options-interface.

* doc/ref/repl-modules.texi (Readline Options): Update, and add entries
  for readline-options, readline-set! et al.

doc/ref/api-debug.texi

@@ -1,6 +1,6 @@
 @c -*-texinfo-*-
 @c This is part of the GNU Guile Reference Manual.
-@c Copyright (C)  1996, 1997, 2000, 2001, 2002, 2003, 2004, 2007, 2010
+@c Copyright (C)  1996, 1997, 2000, 2001, 2002, 2003, 2004, 2007, 2010, 2011
 @c   Free Software Foundation, Inc.
 @c See the file guile.texi for copying conditions.
 
@@ -645,10 +645,13 @@ using @code{debug-set!}.
 
 @deffn {Scheme Procedure} debug-enable option-name
 @deffnx {Scheme Procedure} debug-disable option-name
-@deffnx {Scheme Procedure} debug-set! option-name value
+@deffnx {Scheme Syntax} debug-set! option-name value
 Modify the debug options.  @code{debug-enable} should be used with boolean
 options and switches them on, @code{debug-disable} switches them off.
-@code{debug-set!} can be used to set an option to a specific value.
+
+@code{debug-set!} can be used to set an option to a specific value.  Due
+to historical oddities, it is a macro that expects an unquoted option
+name.
 @end deffn
 
 @subsubheading Stack overflow

doc/ref/api-evaluation.texi

@@ -341,10 +341,13 @@ using @code{read-set!}.
 
 @deffn {Scheme Procedure} read-enable option-name
 @deffnx {Scheme Procedure} read-disable option-name
-@deffnx {Scheme Procedure} read-set! option-name value
+@deffnx {Scheme Syntax} read-set! option-name value
 Modify the read options.  @code{read-enable} should be used with boolean
 options and switches them on, @code{read-disable} switches them off.
-@code{read-set!} can be used to set an option to a specific value.
+
+@code{read-set!} can be used to set an option to a specific value.  Due
+to historical oddities, it is a macro that expects an unquoted option
+name.
 @end deffn
 
 For example, to make @code{read} fold all symbols to their lower case
@@ -416,10 +419,11 @@ quote-keywordish-symbols  reader  How to print symbols that have a colon
                                   not '#f'.
 @end smalllisp
 
-These options may be modified with the print-set! procedure.
+These options may be modified with the print-set! syntax.
 
-@deffn {Scheme Procedure} print-set! option-name value
+@deffn {Scheme Syntax} print-set! option-name value
-Modify the print options.
+Modify the print options.  Due to historical oddities, @code{print-set!}
+is a macro that expects an unquoted option name.
 @end deffn
 
 

doc/ref/api-io.texi

@@ -336,14 +336,6 @@ If @var{pstate} isn't supplied and @var{port} already has
 a print state, the old print state is reused.
 @end deffn
 
-@deffn {Scheme Procedure} print-options-interface [setting]
-@deffnx {C Function} scm_print_options (setting)
-Option interface for the print options. Instead of using
-this procedure directly, use the procedures
-@code{print-enable}, @code{print-disable}, @code{print-set!}
-and @code{print-options}.
-@end deffn
-
 @deffn {Scheme Procedure} simple-format destination message . args
 @deffnx {C Function} scm_simple_format (destination, message, args)
 Write @var{message} to @var{destination}, defaulting to

doc/ref/repl-modules.texi

@@ -1,6 +1,6 @@
 @c -*-texinfo-*-
 @c This is part of the GNU Guile Reference Manual.
-@c Copyright (C)  1996, 1997, 2000, 2001, 2002, 2003, 2004, 2010
+@c Copyright (C)  1996, 1997, 2000, 2001, 2002, 2003, 2004, 2010, 2011
 @c   Free Software Foundation, Inc.
 @c See the file guile.texi for copying conditions.
 
@@ -84,18 +84,21 @@ $endif
 @node Readline Options
 @subsection Readline Options
 
-@c FIXME::martin: Review me!
-
 @cindex readline options
-The readline interface module can be configured in several ways to
+The readline interface module can be tweaked in a few ways to better
-better suit the user's needs.  Configuration is done via the readline
+suit the user's needs.  Configuration is done via the readline module's
-module's options interface, in a similar way to the evaluator and
+options interface, in a similar way to the evaluator and debugging
-debugging options (@pxref{Runtime Options}).
+options (@pxref{Runtime Options}).
+
+@deffn {Scheme Procedure} readline-options
+@deffnx {Scheme Procedure} readline-enable option-name
+@deffnx {Scheme Procedure} readline-disable option-name
+@deffnx {Scheme Syntax} readline-set! option-name value
+Accessors for the readline options.  Note that unlike the enable/disable
+procedures, @code{readline-set!} is syntax, which expects an unquoted
+option name.
+@end deffn
 
-@findex readline-options
-@findex readline-enable
-@findex readline-disable
-@findex readline-set!
 Here is the list of readline options generated by typing
 @code{(readline-options 'help)} in Guile.  You can also see the
 default values.
@@ -107,15 +110,6 @@ bounce-parens   500     Time (ms) to show matching opening parenthesis
                         (0 = off).
 @end smalllisp
 
-The history length specifies how many input lines will be remembered.
-If the history contains that many lines and additional lines are
-entered, the oldest lines will be lost.  You can switch on/off the
-usage of the history file using the following call.
-
-@lisp
-(readline-disable 'history)
-@end lisp
-
 The readline options interface can only be used @emph{after} loading
 the readline module, because it is defined in that module.