CORRECTION * Updated to correctly support bootloader programming w/Optiboot.
Removed ERRORS in Makefile setting incorrect fusebits and lockbits.
Get Optiboot v4.4 from https://code.google.com/p/optiboot/downloads/list
Use Optiboot v4.4, modify target optiboot-target "atmega328" and set AVR_FREQ to
atmega328: AVR_FREQ = 20000000L
Reccomended to also change the LED pin definitions in pin_defs.h of Optiboot:
#define LED_DDR DDRD
#define LED_PORT PORTD
#define LED_PIN PIND
#define LED PIND6