defines/configig include tidy

now just 2 places where config is included...
1) in defines.h
2) At the start of the .ino so it can be made obvious to the user what is happening.

EthernetInterface.cpp

@@ -17,12 +17,6 @@
  *  along with CommandStation.  If not, see <https://www.gnu.org/licenses/>.
  * 
  */
-#if __has_include ( "config.h")
-  #include "config.h"
-#else
-  #warning config.h not found. Using defaults from config.example.h 
-  #include "config.example.h"
-#endif
 #include "defines.h" 
 #if ETHERNET_ON == true
 #include "EthernetInterface.h"

EthernetInterface.h

@@ -22,12 +22,8 @@
 
 #ifndef EthernetInterface_h
 #define EthernetInterface_h
-#if __has_include ( "config.h")
-  #include "config.h"
-#else
-  #warning config.h not found. Using defaults from config.example.h 
-  #include "config.example.h"
-#endif
+
+#include "defines.h")
 #include "DCCEXParser.h"
 #include <Arduino.h>
 #include <avr/pgmspace.h>

LCDDisplay.h

@@ -19,12 +19,9 @@
 #ifndef LCDDisplay_h
 #define LCDDisplay_h
 #include <Arduino.h>
+#include "defines.h"
 #include "DisplayInterface.h"
 
-#if __has_include ( "config.h")
-  #include "config.h"
-#endif
-
 // Allow maximum message length to be overridden from config.h
 #if !defined(MAX_MSG_SIZE) 
 #define MAX_MSG_SIZE 20

defines.h

@@ -22,10 +22,13 @@
 #define DEFINES_H
 
 // defines.h relies on macros defined in config.h
-#if __has_include ( "config.h")
-  #include "config.h"
-#else
-  #include "config.example.h"
+// but it may have already been included (for cosmetic convenence) by the .ino
+#ifndef MOTOR_SHIELD_TYPE
+  #if __has_include ( "config.h")
+    #include "config.h"
+  #else
+    #include "config.example.h"
+  #endif
 #endif
 
 ////////////////////////////////////////////////////////////////////////////////