Added serial message for Z Probe trigger.

Marlin/Configuration.h

   #ifdef Z_PROBE_AND_ENDSTOP
 
 // As of 3-28-2015, there are NO Z Probe pins defined in any board config files.
-// Z_PROBE_PIN is for the signal pin only. RAMPS 1.3/1.4 boards may be able to use the 5V, Ground and the D1 pin in the Aux 1 section of the RAMPS board for the signal.
-// The D1 pin in Aux 1 on RAMPS maps to the Arduino D1 pin. The Z_PROBE_PIN is setting the pin to use on the Arduino. Since the D1 pin on the RAMPS maps to D1 on Arduino, this works.
-// If you have RAMPS 1.3/1.4 and want to use the RAMPS D1 pin, set Z_PROBE_PIN to 1 and use ground and 5v next to it as needed. Check the RAMPS 1.3/1.4 pinout diagram for details.
+// Z_PROBE_PIN is for the signal pin only. RAMPS 1.3/1.4 boards may be able to use the 5V, Ground and the D32 pin in the Aux 4 section of the RAMPS board for the signal.
+// The D32 pin in Aux 4 on RAMPS maps to the Arduino D32 pin. The Z_PROBE_PIN is setting the pin to use on the Arduino. Since the D32 pin on the RAMPS maps to D32 on Arduino, this works.
+// If you have RAMPS 1.3/1.4 and want to use the RAMPS D32 pin, set Z_PROBE_PIN to 32 and use ground and 5v next to it as needed. Check the RAMPS 1.3/1.4 pinout diagram for details.
 // WARNING: Setting the wrong pin may have unexpected and disastrous outcomes. Use with caution and do your homework.
   #define Z_PROBE_PIN -1
 

Marlin/Marlin_main.cpp

     SERIAL_PROTOCOLPGM(MSG_Z2_MAX);
     SERIAL_PROTOCOLLN(((READ(Z2_MAX_PIN)^Z2_MAX_ENDSTOP_INVERTING)?MSG_ENDSTOP_HIT:MSG_ENDSTOP_OPEN));
   #endif
-  
+  #if defined(Z_PROBE_PIN) && Z_PROBE_PIN >-1
+    SERIAL_PROTOCOLPGM(MSG_Z_PROBE);
+    SERIALPROTOCOLLN(((READ(Z_PROBE_PIN)^72Z_PROBE_ENDSTOP_INVERTING)?MSG_ENDSTOP_HIT:MSG_ENDSTOP_OPEN));
+  #endif
 }
 
 /**

Marlin/language.h

 #define MSG_Z_MIN                           "z_min: "
 #define MSG_Z_MAX                           "z_max: "
 #define MSG_Z2_MAX                          "z2_max: "
+#define MSG_Z_PROBE							"z_probe: "
 #define MSG_M119_REPORT                     "Reporting endstop status"
 #define MSG_ENDSTOP_HIT                     "TRIGGERED"
 #define MSG_ENDSTOP_OPEN                    "open"