Minor cast.framework changes

ext/src/shim/framework/classes/CastSession.ts

@@ -25,7 +25,7 @@ type EventHandler = (eventData:
 type MessageListener = (namespace: string, message: string) => void;
 
 
-export default class RemotePlayer {
+export default class CastSession {
     constructor (sessionObj: Session, state: string) {
         console.info("STUB :: CastSession#constructor");
     }

ext/src/shim/framework/index.ts

@@ -44,16 +44,22 @@ export default {
   , RemotePlayer, RemotePlayerChangedEvent, RemotePlayerController
   , SessionStateEventData, VolumeEventData
 
-  , CastContext: Object.assign(CastContext, {
-        getInstance () {
+    /**
+     * CastContext class with an extra getInstance method used to
+     * instantiate and fetch a singleton instance.
+     */
+  , CastContext: {
+        ...CastContext
+
+      , getInstance () {
             if (castContext) {
-                return castContext;
+                return castContext
             }
 
             castContext = new CastContext();
             return castContext;
         }
-    })
+    }
 
   , VERSION: "1.0.07"