Make D-Star, System Fusion, M17, and POCSAG optional.

CalDStarTX.h

@@ -16,10 +16,13 @@
  *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  */
 
+#include "Config.h"
+
+#if defined(MODE_DSTAR)
+
 #if !defined(CALDSTARTX_H)
 #define  CALDSTARTX_H
 
-#include "Config.h"
 #include "DStarDefines.h"
 
 class CCalDStarTX {
@@ -37,3 +40,5 @@ private:
 
 #endif
 
+#endif
+