Plane: separate out auto and guided VTOL states

this prevents a switch to AUTO from using VTOL mode incorrectly

ArduPlane/ArduPlane.cpp

@@ -563,7 +563,7 @@ void Plane::update_flight_mode(void)
         break;
 
     case GUIDED:
-        if (auto_state.vtol_mode && quadplane.available()) {
+        if (auto_state.vtol_guided && quadplane.available()) {
             quadplane.guided_update();
             break;
         }

ArduPlane/Plane.h

@@ -502,8 +502,11 @@ private:
         // barometric altitude at start of takeoff
         float baro_takeoff_alt;
 
-        // are we in VTOL mode?
+        // are we in VTOL mode in AUTO?
         bool vtol_mode:1;
+
+        // are we doing GUIDED mode as a VTOL?
+        bool vtol_guided:1;
     } auto_state;
 
     struct {

ArduPlane/commands.cpp

@@ -97,7 +97,7 @@ void Plane::set_guided_WP(void)
     loiter.start_time_ms = 0;
 
     // start in non-VTOL mode
-    auto_state.vtol_mode = false;
+    auto_state.vtol_guided = false;
     
     loiter_angle_reset();
 }

ArduPlane/navigation.cpp

@@ -175,7 +175,7 @@ void Plane::update_loiter(uint16_t radius)
     if (loiter.start_time_ms != 0 &&
         quadplane.available() &&
         quadplane.guided_mode != 0) {
-        auto_state.vtol_mode = true;
+        auto_state.vtol_guided = true;
     } else if (loiter.start_time_ms == 0 &&
         control_mode == AUTO &&
         !auto_state.no_crosstrack &&

ArduPlane/quadplane.cpp

@@ -1100,7 +1100,7 @@ bool QuadPlane::in_vtol_mode(void)
             plane.control_mode == QLOITER ||
             plane.control_mode == QLAND ||
             plane.control_mode == QRTL ||
-            (plane.control_mode == GUIDED && plane.auto_state.vtol_mode) ||
+            (plane.control_mode == GUIDED && plane.auto_state.vtol_guided) ||
             in_vtol_auto());
 }
 

ArduPlane/system.cpp

@@ -382,6 +382,7 @@ void Plane::set_mode(enum FlightMode mode)
 
     // assume non-VTOL mode
     auto_state.vtol_mode = false;
+    auto_state.vtol_guided = false;
     
     switch(control_mode)
     {
@@ -784,7 +785,7 @@ void Plane::frsky_telemetry_send(void)
  */
 int8_t Plane::throttle_percentage(void)
 {
-    if (auto_state.vtol_mode) {
+    if (quadplane.in_vtol_mode()) {
         return quadplane.throttle_percentage();
     }
     // to get the real throttle we need to use norm_output() which