Changes to integrate into WSJT-X build system

A  separate install  of the  portaudio  library is  now required,  see
"doc/building on MS Windows.txt" for a suitable recipe.

The map65  code base  is still  MS Windows specific  in some  areas so
don't expect successful builds on Linux or macOS yet.

map65/soundin.cpp

@@ -331,9 +331,7 @@ void SoundInThread::inputUDP()
   }
 
   // Set this socket's total buffer space for received UDP packets
-  int v=141600;
-  ::setsockopt(udpSocket->socketDescriptor(), SOL_SOCKET, SO_RCVBUF,
-               (char *)&v, sizeof(v));
+  udpSocket->setSocketOption (QUdpSocket::ReceiveBufferSizeSocketOption, 141600);
 
   bool qe = quitExecution;
   struct linradBuffer {