refactor(Store): don't export internal functions and tokens (#1679)

Closes #1657 

BREAKING CHANGE:

Internal functions and tokens are removed from the public API

modules/store/src/index.ts

@@ -35,24 +35,15 @@ export {
 export { State, StateObservable, reduceState } from './state';
 export {
   INITIAL_STATE,
-  _REDUCER_FACTORY,
   REDUCER_FACTORY,
-  _INITIAL_REDUCERS,
   INITIAL_REDUCERS,
   STORE_FEATURES,
-  _INITIAL_STATE,
   META_REDUCERS,
-  _STORE_REDUCERS,
-  _FEATURE_REDUCERS,
   FEATURE_REDUCERS,
-  _FEATURE_REDUCERS_TOKEN,
   USER_PROVIDED_META_REDUCERS,
 } from './tokens';
 export {
   StoreModule,
   StoreRootModule,
   StoreFeatureModule,
-  _initialStateFactory,
-  _createStoreReducers,
-  _createFeatureReducers,
 } from './store_module';

modules/store/src/tokens.ts

@@ -9,7 +9,7 @@ export const REDUCER_FACTORY = new InjectionToken(
   '@ngrx/store Reducer Factory'
 );
 export const _REDUCER_FACTORY = new InjectionToken(
-  '@ngrx/store Reducer Factory Provider'
+  '@ngrx/store Internal Reducer Factory Provider'
 );
 export const INITIAL_REDUCERS = new InjectionToken(
   '@ngrx/store Initial Reducers'