RNA

RNA

* ID blocks can now get RNA properties defined from python, e.g.:
  bpy.types.Scene.BoolProperty(..)
* RNA structs/functions/properties can now get pointers duplicated
  (mostly strings), since we can't point to some static string then.
* Added ExtensionRNA struct to add into *Type structs for subclassing,
  is a bit more compact than defining the 4 variables each time.
  Only disadvantage is it requires including RNA in more places.