[#22488] Reloading scripts causes crash

F8 key enabled again, useful for script UI development.

- keying set freeing wasnt freeing from all scenes and the builtin list.
- PointerProperty() cant refer to a removed python srna type (fixed in rigify and netrender).
- Added a check for freeing a type used by a PointerProperty but its very slow, makes reloading take ~10sec. Only enabled this in debug mode for now.

Netrender register() function isnt re-registering the property, probably because the module is cached by python and not re-run.

source/blender/python/intern/bpy_rna.h

@@ -86,10 +86,6 @@ int pyrna_set_to_enum_bitfield(EnumPropertyItem *items, PyObject *value, int *r_
 
 int pyrna_enum_value_from_id(EnumPropertyItem *item, const char *identifier, int *value, const char *error_prefix);
 
-/* function for registering types */
-PyObject *pyrna_basetype_register(PyObject *self, PyObject *args);
-PyObject *pyrna_basetype_unregister(PyObject *self, PyObject *args);
-
 int pyrna_deferred_register_props(struct StructRNA *srna, PyObject *class_dict);
 
 /* called before stopping python */