Tag-enabled registries must now be registered to vanilla's root registry. See RegistryBuilder#hasTags.
Modded tag-enabled registries have to use the format `data/<namespace>/tags/<registrynamespace>/<registryname>/<tag>.json`
This format is to prevent conflicts for registries with the same path but different namespaces
EX: Registry name `examplemod:shoe`, tag name `blue_shoes` would be `data/<namespace>/tags/examplemod/shoe/blue_shoes.json`
RegistryEvent.NewRegistry has been moved and renamed to NewRegistryEvent.
RegistryBuilder#create has been made private. See NewRegistryEvent#create
Created new ITagManager system for looking up Forge tags. See IForgeRegistry#tags.
Add lookup methods for Holders from forge registries. See IForgeRegistry#getHolder.