refs #310, used empty network context with runtime/context base classes

* refactored to member initialization
* adjusted asserts
* adjusted isXXObject methods
* changed create method for ContextNetwork to support empty context
* empty status message used as return value in empty context

src/blackcore/context_network.h

@@ -192,7 +192,6 @@ namespace BlackCore
     protected:
         //! Constructor
         IContextNetwork(CRuntimeConfig::ContextMode mode, CRuntime *runtime) : CContext(mode, runtime) {}
-
     };
 }