Improve error handling by displaying an error message (#1075)

* wire up error messages

* more errors

* fix crash on render error

* Always show copy and cut

* PR comments

* Fix spelling

src/GraphControl/Control/Grapher.h

@@ -335,6 +335,8 @@ public
         bool m_Moving;
         Windows::UI::Xaml::DispatcherTimer ^ m_TracingTrackingTimer;
         Windows::UI::Core::CoreCursor ^ m_cachedCursor;
+        int m_errorType;
+        int m_errorCode;
 
     public:
         Windows::Storage::Streams::RandomAccessStreamReference ^ GetGraphBitmapStream();