Introduced an easier Facade class to access mod integration abstractions (called Integrations). Removed the link between IntegrationType and integration abstraction. Integrations are now explicitly instantiated inside of IntegrationNode.
Removes the improper way to set itself into a public static non-final variable.
Removes the direct access to the IntegrationRegistry from AppEng. Will be added at some later point somewhere else for non-singleton access.
Constructor is set to package private to enable possible construction from unit tests. Are current not runnable sind it is currently tied to the FML Loader instance.