Add TODO about strongly typing variable

Author: amaitland

CefSharp.BrowserSubprocess.Core/JavascriptPropertyWrapper.h

@@ -17,6 +17,7 @@ namespace CefSharp
         JavascriptProperty^ _javascriptProperty;
         int64 _ownerId;
         IBrowserProcess^ _browserProcess;
+        //TODO: Strongly type this variable - currently trying to include JavascriptObjectWrapper.h creates a circular reference, so won't compile
         Object^ _javascriptObjectWrapper;
     internal:
         MCefRefPtr<CefV8Value> V8Value;