Fixes #2595 - Cli added

Based on projectkk2glider work, with a lot of bugs I am sure. Still not
tested, this is why I preferred working on my own branch. I push it now
so that Jenkins do the first tests and you can review if I am on the
right track. 

I am really wondering if a merge with the Lua api would be possible /
nice, what do you think?

radio/src/telemetry/frsky.cpp

@@ -165,8 +165,8 @@ NOINLINE void processSerialData(uint8_t data)
 #endif
 
 #if defined(PCBTARANIS)
-    if (g_eeGeneral.uart3Mode == UART_MODE_TELEMETRY_MIRROR) {
-      uart3Putc(data);
+    if (g_eeGeneral.serial2Mode == UART_MODE_TELEMETRY_MIRROR) {
+      serial2Putc(data);
     }
 #endif
 
@@ -604,7 +604,7 @@ void telemetryInit(void)
   }
   else if (telemetryProtocol==PROTOCOL_FRSKY_D_SECONDARY) {
     telemetryPortInit(0);
-    telemetrySecondPortInit(PROTOCOL_FRSKY_D_SECONDARY);
+    serial2TelemetryInit(PROTOCOL_FRSKY_D_SECONDARY);
   }
   else {
     telemetryPortInit(FRSKY_SPORT_BAUDRATE);