added support for TIMER4D used for PWM on Leonardo and Micro D6

cores/arduino/Arduino.h

@@ -169,9 +169,10 @@ extern const uint8_t PROGMEM digital_pin_to_timer_PGM[];
 #define TIMER4A 11
 #define TIMER4B 12
 #define TIMER4C 13
-#define TIMER5A 14
-#define TIMER5B 15
-#define TIMER5C 16
+#define TIMER4D 14	
+#define TIMER5A 15
+#define TIMER5B 16
+#define TIMER5C 17
 
 #ifdef __cplusplus
 } // extern "C"

cores/arduino/wiring_analog.c

@@ -226,6 +226,14 @@ void analogWrite(uint8_t pin, int val)
 				break;
 			#endif
 				
+			#if defined(TCCR4A) && defined(COM4D1)
+			case TIMER4D:
+				// connect pwm to pin on timer 4, channel D
+				sbi(TCCR4A, COM4D1);
+				OCR4D = val; // set pwm duty
+				break;
+			#endif
+
 			#if defined(TCCR5A) && defined(COM5A1)
 			case TIMER5A:
 				// connect pwm to pin on timer 5, channel A