Support for multiple displays (OLED etc).

New EXRAIL command LCD2(display,row,"text").  Display 0 is the usual one, other displays can be configured through HAL.

EXRAIL2.h

@@ -73,11 +73,15 @@ enum OPCODE : byte {OPCODE_THROW,OPCODE_CLOSE,
              OPCODE_IFLOCO
              };
 
+// Ensure thrunge_lcd is put last as there may be more than one display, 
+// sequentially numbered from thrunge_lcd.
 enum thrunger: byte {
   thrunge_print, thrunge_broadcast, thrunge_serial,thrunge_parse,
   thrunge_serial1, thrunge_serial2, thrunge_serial3,
   thrunge_serial4, thrunge_serial5, thrunge_serial6,
-  thrunge_lcd, thrunge_lcn};
+  thrunge_lcn, 
+  thrunge_lcd,  // Must be last!!
+  };