Reliably sort json data structures.

- Use murmur3 hashes for fast hashing and comparison of objects which
  fail comparison with the normal <=> operator, and sort on hashes of
  their string values instead.  I suppose we may be able to sort on
  string value altogether in this case...
- Fix some bugs.
- Add and fix tests
- Remove the resource_utils_spec_helper which is no longer needed.