Add parameter to FRN module to start with disabled RF

src/doc/man/ModuleFrn.conf.5

@@ -91,6 +91,10 @@ Network (room) where to connect, each server holds up to 32 networks (rooms).
 .B FRN_DEBUG
 Define to enable extensive module logging, including FRN request and response
 printout.
+.TP
+.B DISABLE_RF
+Define to disable sending voice from FRN to RIG. In other words, nothing will
+be transmitted by radio (count be switched on by DTMF command later if needed)
 .
 .SH FRN NEW USER REGISTRATION
 To register at FRN service it is possible to use native desktop client or just

src/svxlink/modules/frn/ModuleFrn.conf

@@ -4,7 +4,7 @@ PLUGIN_NAME=Frn
 ID=4
 TIMEOUT=300
 
-; http://freeradionetwork.eu/frnprotocol.htm
+; Details http://freeradionetwork.eu/frnprotocol.htm
 SERVER=127.0.0.1
 PORT=10024
 VERSION=2014000
@@ -18,3 +18,5 @@ COUNTRY=Antarctica
 CITY_CITY_PART="City - Street"
 NET=Test
 
+;FRN_DEBUG=1
+;DISABLE_RF=1

src/svxlink/modules/frn/QsoFrn.cpp

@@ -151,6 +151,9 @@ QsoFrn::QsoFrn(ModuleFrn *module)
   if (cfg.getValue(cfg_name, "FRN_DEBUG", opt_frn_debug))
     cout << "frn debugging is enabled" << endl;
 
+  if (cfg.getValue(cfg_name, "DISABLE_RF", is_rf_disabled))
+    cout << "rf is disabled" << endl;
+
   if (!cfg.getValue(cfg_name, "SERVER", opt_server))
   {
     cerr << "*** ERROR: Config variable " << cfg_name