Copter: add option to disable GUIDED_NOGPS flight mode

Saves about 6.3kB of flash

ArduCopter/APM_Config.h

@@ -27,6 +27,7 @@
 //#define MODE_BRAKE_ENABLED    DISABLED            // disable brake mode support
 //#define MODE_DRIFT_ENABLED    DISABLED            // disable drift mode support
 //#define MODE_GUIDED_ENABLED   DISABLED            // disable guided mode support
+//#define MODE_GUIDED_NOGPS_ENABLED   DISABLED      // disable guided/nogps mode support
 //#define MODE_LOITER_ENABLED   DISABLED            // disable loiter mode support
 //#define MODE_POSHOLD_ENABLED  DISABLED            // disable poshold mode support
 //#define MODE_RTL_ENABLED DISABLED                 // disable rtl mode support

ArduCopter/Copter.h

@@ -995,7 +995,9 @@ private:
     ModeAvoidADSB mode_avoid_adsb;
 #endif
     ModeThrow mode_throw;
+#if MODE_GUIDED_NOGPS_ENABLED == ENABLED
     ModeGuidedNoGPS mode_guided_nogps;
+#endif
 #if MODE_SMARTRTL_ENABLED == ENABLED
     ModeSmartRTL mode_smartrtl;
 #endif

ArduCopter/config.h

@@ -291,6 +291,12 @@
 # define MODE_GUIDED_ENABLED ENABLED
 #endif
 
+//////////////////////////////////////////////////////////////////////////////
+// GuidedNoGPS mode - control vehicle's angles from GCS
+#ifndef MODE_GUIDED_NOGPS_ENABLED
+# define MODE_GUIDED_NOGPS_ENABLED ENABLED
+#endif
+
 //////////////////////////////////////////////////////////////////////////////
 // Loiter mode - allows vehicle to hold global position
 #ifndef MODE_LOITER_ENABLED

ArduCopter/mode.cpp

@@ -126,9 +126,11 @@ Copter::Mode *Copter::mode_from_mode_num(const uint8_t mode)
             break;
 #endif
 
+#if MODE_GUIDED_NOGPS_ENABLED == ENABLED
         case GUIDED_NOGPS:
             ret = &mode_guided_nogps;
             break;
+#endif
 
 #if MODE_SMARTRTL_ENABLED == ENABLED
         case SMART_RTL: