python modules in the game engine could point to builtin modules like GameLogic that was cleared.

I added module clearing before there was checks for invalid python objects, so now its not needed for BGE Builtin types at least.

also made the builtin modules get re-used if they already exist and clear all user modules when the game engine finishes so with Module-Py-Controllers the referenced modules are at least up to date when pressing Pkey.

source/blender/python/api2_2x/bpy_internal_import.h

@@ -37,7 +37,7 @@
 
 PyObject*	bpy_text_import( char *name, int *found );
 PyObject*	bpy_text_reimport( PyObject *module, int *found );
-void		bpy_text_clear_modules( void ); /* Clear user modules */
+void		bpy_text_clear_modules( int clear_all ); /* Clear user modules */
 extern PyMethodDef bpy_import_meth[];
 extern PyMethodDef bpy_reload_meth[];