LCC and signal compile-out

LCC commands in EXRAIL for OpenMRN Adapter

FIrst use of compile-out of unused features.

DCCEXParser.cpp

@@ -67,7 +67,7 @@ Once a new OPCODE is decided upon, update this list.
   k, Reserved for future use - Potentially Railcom
   K, Reserved for future use - Potentially Railcom
   l, Loco speedbyte/function map broadcast
-  L,
+  L, Reserved for LCC interface (implemented in EXRAIL)
   m,
   M, Write DCC packet
   n,
@@ -906,6 +906,9 @@ void DCCEXParser::parseOne(Print *stream, byte *com, RingStream * ringStream)
         break;
 #endif
 
+    case 'L': // LCC interface implemented in EXRAIL parser
+        break; // Will <X> if not intercepted by EXRAIL 
+
     default: //anything else will diagnose and drop out to <X>
         DIAG(F("Opcode=%c params=%d"), opcode, params);
         for (int i = 0; i < params; i++)