Added ability to manually enable/disable probe pin

Marlin/Conditionals_LulzBot.h

@@ -396,6 +396,14 @@
     #define LULZBOT_ENABLE_PROBE_PINS(enable)
 #endif
 
+/* Make it so M42 S<state> controls the state of the
+/* probe lines. This is useful for troubleshooting. */
+#define LULZBOT_M42_TOGGLES_PROBE_PINS \
+    if (!parser.seenval('P')) { \
+      LULZBOT_ENABLE_PROBE_PINS(pin_status); \
+      return; \
+    }
+
 #define LULZBOT_FAN_KICKSTART_TIME          100
 #define LULZBOT_FAN_MIN_PWM                  70
 #define LULZBOT_HOST_KEEPALIVE_FEATURE_DISABLED

Marlin/Marlin_main.cpp

@@ -6434,6 +6434,8 @@ inline void gcode_M42() {
   if (!parser.seenval('S')) return;
   const byte pin_status = parser.value_byte();
 
+  LULZBOT_M42_TOGGLES_PROBE_PINS
+
   const int pin_number = parser.intval('P', LED_PIN);
   if (pin_number < 0) return;