Rover: rename set_next_WP to set_auto_WP to clarify usage

APMrover2/Rover.h

@@ -469,7 +469,7 @@ private:
     void calc_lateral_acceleration();
     void calc_nav_steer();
     void set_servos(void);
-    void set_next_WP(const struct Location& loc);
+    void set_auto_WP(const struct Location& loc);
     void set_guided_WP(const struct Location& loc);
     void init_home();
     void restart_nav();

APMrover2/commands.cpp

@@ -5,14 +5,14 @@
     void set_guided_WP(void)
     void init_home()
     void restart_nav()
-************************************************************ 
+************************************************************
 */
 
 
 /*
- *  set_next_WP - sets the target location the vehicle should fly to
+ *  set_auto_WP - sets the target location the vehicle should drive to in Auto mode
  */
-void Rover::set_next_WP(const struct Location& loc)
+void Rover::set_auto_WP(const struct Location& loc)
 {
     // copy the current WP into the OldWP slot
     // ---------------------------------------

APMrover2/commands_logic.cpp

@@ -236,7 +236,7 @@ void Rover::do_nav_wp(const AP_Mission::Mission_Command& cmd)
 
     Location cmdloc = cmd.content.location;
     location_sanitize(current_loc, cmdloc);
-    set_next_WP(cmdloc);
+    set_auto_WP(cmdloc);
 }
 
 void Rover::do_loiter_unlimited(const AP_Mission::Mission_Command& cmd)