Python runtime now supports meta-accessors

Some highlights of what got us there:
  - Stricter port names such that they are legal variables in every
    language. It's not worth keeping munged / "clean" things around
    that are different between code and what's actually there
  - Strict enforcement of `subinit`. The meta-accessor cannot refernce
    the subaccessor until it inits it, prevents accidental cheating
  - Clean up some buggy accessor code that had been relying on the
    looser web environment