Disable Chicken target language

Clean up to disable target languages that have been neglected/not functional.
Target language be fully deleted in SWIG 4.1 unless a new maintainer brings
it up to an acceptable status (experimental or supported).

Issue #1447

Doc/Devel/runtime.txt

@@ -57,7 +57,7 @@ Alternatively, if the language supports modules, a module named
 named "type_table" SWIG_TYPE_TABLE_NAME can be created inside it.  The most
 common approach is to store the mod pointer in some global variable in the
 target language, but if the language provides an alternative place to store data
-(like the chicken module), then that is good too.
+then that is good too.
 
 The way the code is set up, SetModule should only be called when GetModule
 returns NULL, and if SetModule is called a second time, the behavior is
@@ -105,7 +105,7 @@ Standard Functions
 These functions are not required and their API is not formalized, but almost all
 language modules implement them for consistency across languages.  Throughout
 this discussion, I will use LangType to represent the underlying language type
-(C_word in chicken, Scheme_Object * in mzscheme, PyObject * in python, etc)
+(Scheme_Object * in mzscheme, PyObject * in python, etc)
 
 
 

Doc/Manual/Preprocessor.html

@@ -111,7 +111,6 @@ SWIG_VERSION                    Hexadecimal (binary-coded decimal) number contai
 
 SWIGALLEGROCL                   Defined when using Allegro CL
 SWIGCFFI                        Defined when using CFFI
-SWIGCHICKEN                     Defined when using CHICKEN
 SWIGCSHARP                      Defined when using C#
 SWIGGUILE                       Defined when using Guile
 SWIGJAVA                        Defined when using Java

Doc/Manual/SWIG.html

@@ -119,7 +119,6 @@ for example, <tt>swig -ruby -help</tt> for Ruby.
 <div class="shell"><pre>
 Supported Target Language Options
      -allegrocl      - Generate ALLEGROCL wrappers
-     -chicken        - Generate CHICKEN wrappers
      -cffi           - Generate CFFI wrappers
      -csharp         - Generate C# wrappers
      -d              - Generate D wrappers

Doc/Manual/Sections.html

@@ -42,7 +42,6 @@ Last update : SWIG-4.0.0 (in progress)
 <li><a href="Allegrocl.html#Allegrocl">Allegro Common Lisp support</a></li>
 <li><a href="Android.html#Android">Android support</a></li>
 <li><a href="CSharp.html#CSharp">C# support</a></li>
-<li><a href="Chicken.html#Chicken">Chicken support</a></li>
 <li><a href="D.html#D">D support</a></li>
 <li><a href="Go.html#Go">Go support</a></li>
 <li><a href="Guile.html#Guile">Guile support</a></li>

Doc/Manual/chapters

@@ -20,7 +20,6 @@ CCache.html
 Allegrocl.html
 Android.html
 CSharp.html
-Chicken.html
 D.html
 Go.html
 Guile.html