Copter: remove unused AUTO_SLEW_RATE parameter

ArduCopter/Parameters.h

@@ -139,7 +139,7 @@ public:
         k_param_optflow_enabled,
         k_param_low_voltage,
         k_param_ch7_option,
-        k_param_auto_slew_rate,
+        k_param_auto_slew_rate,     // deprecated - can be deleted
         k_param_sonar_type,
         k_param_super_simple = 155,
         k_param_axis_enabled = 157,
@@ -339,7 +339,6 @@ public:
     AP_Int8         frame_orientation;
     AP_Int8         ch7_option;
     AP_Int8         ch8_option;
-    AP_Int16        auto_slew_rate;
 
 #if FRAME_CONFIG ==     HELI_FRAME
     // Heli

ArduCopter/Parameters.pde

@@ -419,15 +419,6 @@ const AP_Param::Info var_info[] PROGMEM = {
     // @User: Standard
     GSCALAR(ch8_option, "CH8_OPT",                  CH8_OPTION),
 
-	// @Param: AUTO_SLEW
-    // @DisplayName: Auto Slew Rate
-    // @Description: This restricts the rate of change of the roll and pitch attitude commanded by the auto pilot
-    // @Units: Degrees/Second
-	// @Range: 1 90
-    // @Increment: 1
-    // @User: Advanced
-    GSCALAR(auto_slew_rate, "AUTO_SLEW",            AUTO_SLEW_RATE),
-
 #if FRAME_CONFIG ==     HELI_FRAME
     GGROUP(heli_servo_1,    "HS1_", RC_Channel),
     GGROUP(heli_servo_2,    "HS2_", RC_Channel),

ArduCopter/config.h

@@ -882,10 +882,6 @@
 //////////////////////////////////////////////////////////////////////////////
 // Autopilot rotate rate limits
 //
-#ifndef AUTO_SLEW_RATE
- # define AUTO_SLEW_RATE         	45                     // degrees/sec
-#endif
-
 #ifndef AUTO_YAW_SLEW_RATE
  # define AUTO_YAW_SLEW_RATE        60                     // degrees/sec
 #endif