Storing next track and pre-fetching artwork for snappier UI

src/js/services/core/middleware.js

@@ -316,7 +316,7 @@ const CoreMiddleware = (function(){
             case 'CURRENT_TRACK_LOADED':
                 store.dispatch({
                     type: 'TRACKS_LOADED',
-                    tracks: [action.current_track]
+                    tracks: [action.track]
                 });
 
                 next(action);

src/js/services/core/reducer.js

@@ -13,8 +13,13 @@ export default function reducer(core = {}, action){
 
         case 'CURRENT_TRACK_LOADED':
             return Object.assign({}, core, {
-                current_track: action.current_track,
-                current_track_uri: action.current_track_uri
+                current_track: action.track,
+                current_track_uri: action.uri
+            });
+
+        case 'NEXT_TRACK_LOADED':
+            return Object.assign({}, core, {
+                next_track_uri: action.uri
             });
 
         case 'QUEUE_LOADED':