Python scripting: make UTF8 class accessible by python scripts. Add python method GetChars() to UTF8 class to get its char buffer.

See scripts/test_kicad_plugin.py for example.

scripting/kicad.i

@@ -53,6 +53,7 @@
 %ignore operator <<;
 %ignore operator=;
 
+
 /* headers/imports that must be included in the _wrapper.cpp at top */
 
 %{
@@ -62,7 +63,7 @@
     #include <common.h>
     #include <wx_python_helpers.h>
     #include <cstddef>
-      #include <vector>
+    #include <vector>
 
     #include <class_title_block.h>
     #include <class_colors_design_settings.h>
@@ -70,7 +71,6 @@
     #include <eda_text.h>
     #include <convert_from_iu.h>
     #include <convert_to_biu.h>
-
 %}
 
 /* all the wx wrappers for wxString, wxPoint, wxRect, wxChar .. */
@@ -110,7 +110,30 @@
 
 /* std template mappings */
 %template(intVector) std::vector<int>;
+%template(str_utf8_Map) std::map< std::string,UTF8 >;
 
 /* KiCad plugin handling */
 %include "kicadplugins.i"
 
+// ignore warning relative to operator = and operator ++:
+#pragma SWIG nowarn=362,383
+
+// Rename operators defined in utf8.h
+%rename(utf8_to_charptr) operator char* () const;
+%rename(utf8_to_wxstring) operator wxString () const;
+
+#include <utf8.h>
+%include <utf8.h>
+
+%extend UTF8
+{
+    const char*   Cast_to_CChar()    { return (self->c_str()); }
+
+    %pythoncode
+    {
+
+    def GetChars(self):
+        return self.Cast_to_CChar()
+    }
+}
+