Blender Git Loki

fix for error comparing py-struct members

if 2 pyrna structs used the same pointer they could incorrectly compare as true, this caused an error in theme saving because an item could match its parent and stop writing (to prevent recursive writing of same data).

eg:
context.user_preferences.themes[0].user_interface.wcol_regular == context.user_preferences.themes[0].user_interface