The next major release.

Placeholder for discussing next major release.

The goal for next release:

* Cleanup code and simplify architecture.
* Reporters. Only 3 types now. `array`, `hash`, and `message`. They use formatters to format messages.
* Support custom Reporter with configuration.
* Formatters. Comes with `human` and `machine` flavors.
* Support custom Formatters.
* Support `model.errors.format(:machine).to_hash`.