Adding missing IsBusy implementations

Author: StanleyGoldman

src/UnityExtension/Assets/Editor/GitHub.Unity/UI/LoadingView.cs

@@ -25,5 +25,10 @@ public override void InitializeView(IView parent)
 
         public override void OnGUI()
         {}
+
+        public override bool IsBusy
+        {
+            get { return false; }
+        }
     }
 }

src/UnityExtension/Assets/Editor/GitHub.Unity/UI/PopupWindow.cs

@@ -93,6 +93,11 @@ public override void OnSelectionChange()
             ActiveView.OnSelectionChange();
         }
 
+        public override bool IsBusy
+        {
+            get { return ActiveView.IsBusy; }
+        }
+
         public override void Finish(bool result)
         {
             OnClose.SafeInvoke(result);