tterrag is a meany face and yelled at me for using class.getSimpleName(). So here's an API-friendly re-work of the registration system. This allows all our Items/Blocks to be obtained via the API. Just add a new enum.
The blocks in this list cannot be changed via config file. The two lists are kept (instead just one) so that the config one can be refreshed at any point with ConfigChangedEvent.