[ Avaa Bypassed ]

## Unreleased
- Fixes stringify to only take ancestors into account when checking
  circularity.  
  It previously assumed every visited object was circular which led to [false
  positives][issue9].  
  Uses the tiny serializer I wrote for [Must.js][must] a year and a half ago.
- Fixes calling the `replacer` function in the proper context (`thisArg`).
- Fixes calling the `cycleReplacer` function in the proper context (`thisArg`).
- Speeds serializing by a factor of
  Big-O(h-my-god-it-linearly-searched-every-object) it had ever seen. Searching
  only the ancestors for a circular references speeds up things considerably.

[must]: https://github.com/moll/js-must
[issue9]: https://github.com/isaacs/json-stringify-safe/issues/9