Remove unused variables from list() calls in SecureString. Put an exception handler around openssl_decrypt() to catch warnings.
Validation refactor.

- Allow an http status code as the third argument of Validation->addError().
- Allow Validation->addError to take an entire field array from the schema and not just the name.
- Check for an error code that has a %s before adding one.
Schema tweaks.

- Make Schema JsonSerializable.
- Add more valid strings to boolean types.
- Fix some logic.
Implement around a SecureString edge case.

- Sometimes a string will decrypt, but return garbage. In this case just throw a 403 if the json won’t serialize.