Drop support for python 3.1.

for building py3.2 on *nix see:
  http://wiki.blender.org/index.php?title=Dev:2.5/Doc/Building_Blender/Linux/Troubleshooting#Python

also fixed possible buffer overrun with getting the fake filepath for a blender textblock.

source/blender/python/generic/bpy_internal_import.h

@@ -52,7 +52,7 @@ PyObject*	bpy_text_import_name(char *name, int *found);
 PyObject*	bpy_text_reimport(PyObject *module, int *found);
 /* void		bpy_text_clear_modules(int clear_all);*/ /* Clear user modules */ 
 
-void bpy_text_filename_get(char *fn, struct Text *text);
+void bpy_text_filename_get(char *fn, size_t fn_len, struct Text *text);
 
 extern PyMethodDef bpy_import_meth;
 extern PyMethodDef bpy_reload_meth;