Tidy up DX Lab and HRD interface implementations

Applied techniques  learned from  dealing with  HRD quirks  and TCP/IP
client   issues   on  Windows   to   the   DX  Lab   Suite   Commander
interface. These changes should hopefully make both the HRD and DX Lab
Suite CAT  interfacing more robust  in the  face of network  and other
latency issues or server failures.

git-svn-id: svn+ssh://svn.code.sf.net/p/wsjt/wsjt/branches/wsjtx@4296 ab8295b8-cf94-4d9e-aec4-7959e3be5d79

DXLabSuiteCommanderTransceiver.hpp

@@ -3,12 +3,11 @@
 
 #include <memory>
 
-#include <QByteArray>
-
 #include "TransceiverFactory.hpp"
 #include "PollingTransceiver.hpp"
 
 class QTcpSocket;
+class QByteArray;
 
 //
 // DX Lab Suite Commander Interface
@@ -43,6 +42,7 @@ protected:
 private:
   void simple_command (QByteArray const&, bool no_debug = false);
   QByteArray command_with_reply (QByteArray const&, bool no_debug = false);
+  bool write_to_port (QByteArray const&);
 
   std::unique_ptr<TransceiverBase> wrapped_;
   bool use_for_ptt_;