Use the native CSON.stringify from cson-safe@0.2.0
Updated tests to reflect cson-safe CSON.stringify:

https://github.com/groupon/cson-safe/pull/9
Spec change: like JSON.stringify, functions in objects are silently filtered
Updated to less brace-heavy serialized cson
Addressing feedback: be consistent with JSON.stringify
Merge pull request #3 from johan/CSON.stringify

CSON.stringify