AP_Notify: add gps_glitch flag

libraries/AP_Notify/AP_Notify.h

@@ -32,12 +32,14 @@ public:
     struct notify_type {
         uint16_t initialising       : 1;    // 1 if initialising and copter should not be moved
         uint16_t gps_status         : 2;    // 0 = no gps, 1 = no lock, 2 = 2d lock, 3 = 3d lock
+        uint16_t gps_glitching      : 1;    // 1 if gps position is not good
         uint16_t armed              : 1;    // 0 = disarmed, 1 = armed
         uint16_t pre_arm_check      : 1;    // 0 = failing checks, 1 = passed
         uint16_t save_trim          : 1;    // 1 if gathering trim data
         uint16_t esc_calibration    : 1;    // 1 if calibrating escs
         uint16_t failsafe_radio     : 1;    // 1 if radio failsafe
         uint16_t failsafe_battery   : 1;    // 1 if battery failsafe
+        uint16_t failsafe_gps       : 1;    // 1 if gps failsafe
     };
 
     // the notify flags are static to allow direct class access