Sub: Add WaterDetector object and parameters

ArduSub/Parameters.cpp

@@ -877,6 +877,11 @@ const AP_Param::Info Sub::var_info[] = {
     // @Path: ../libraries/AP_GPS/AP_GPS.cpp
     GOBJECT(gps, "GPS_", AP_GPS),
 
+    // Water driver
+    // @Group: WD_
+    // @Path: ../libraries/AP_WaterDetector/AP_WaterDetector.cpp
+	GOBJECT(water_detector, "WD_", AP_WaterDetector),
+
     // @Group: SCHED_
     // @Path: ../libraries/AP_Scheduler/AP_Scheduler.cpp
     GOBJECT(scheduler, "SCHED_", AP_Scheduler),

ArduSub/Parameters.h

@@ -386,6 +386,8 @@ public:
 		k_param_jbtn_13,
 		k_param_jbtn_14,
 		k_param_jbtn_15, // 276
+
+		k_param_water_detector, // water detector object
     };
 
     AP_Int16        format_version;

ArduSub/Sub.h

@@ -92,6 +92,7 @@
 #include <AP_RPM/AP_RPM.h>
 #include <AC_InputManager/AC_InputManager.h>        // Pilot input handling library
 #include <AP_JSButton/AP_JSButton.h>   // Joystick/gamepad button function assignment
+#include <AP_WaterDetector/AP_WaterDetector.h> // Water detector
 
 // Configuration
 #include "defines.h"
@@ -170,6 +171,8 @@ private:
 
     AP_GPS gps;
 
+    AP_WaterDetector water_detector;
+
     // flight modes convenience array
     AP_Int8 *flight_modes;