Extend std::auto_ptr<> support to Ruby

This is trivial as exactly the same typemap as for Python can be used
for Ruby too, all the differenced are abstracted by the unified typemap
library.

Lib/ruby/std_auto_ptr.i

@@ -0,0 +1,17 @@
+/*
+    The typemaps here allow to handle functions returning std::auto_ptr<>,
+    which is the most common use of this type. If you have functions taking it
+    as parameter, these typemaps can't be used for them and you need to do
+    something else (e.g. use shared_ptr<> which SWIG supports fully).
+ */
+
+%define %auto_ptr(TYPE)
+%typemap (out) std::auto_ptr<TYPE > %{
+   %set_output(SWIG_NewPointerObj($1.release(), $descriptor(TYPE *), SWIG_POINTER_OWN | %newpointer_flags));
+%}
+%template() std::auto_ptr<TYPE >;
+%enddef
+
+namespace std {
+   template <class T> class auto_ptr {};
+}