refs #316 Changed blackcore to use CLogMessage to emit messages.

Also changed functions which always returned CStatusMessageList containing a single CStatusMessage,
to return CStatusMessage instead for simplicity.

src/blackcore/network.h

@@ -65,6 +65,11 @@ namespace BlackCore
          */
         virtual ~INetwork() {}
 
+        /*!
+         * Log message category.
+         */
+        static QString getMessageCategory() { return "swift.trafficNetwork"; }
+
         /*!
          * Flags for capabilities bitfield.
          */