cores: add ATmega128RFA1 core

This core is based on the ATmega1281 core per Atmel's documentation so
that was used as a starting point. No guarentees that the radio is wired
up correctly.
timers: Reformat

Cleanup the macros

Signed-off-by: Michel Pollet <buserror@gmail.com>
Merge pull request #50 from cardoe/atmega128rfa1

cores: add ATmega128RFA1 core
uart: refactor uart udr write operation outside generic uart write.

	modified:   simavr/sim/avr_uart.c
core: Removed trace crash macro

Made it a function instead.

Reworked from nnayo's commit
core: Handle EIND register

Parts with more than 128KB of flash need an extra byte on the stack
Rework from nnayo branch for the atmega2560

Signed-off-by: Michel Pollet <buserror@gmail.com>
cores: Add atmega2560
Merge pull request #54 from bsekisser/uart-udr-write-changes

uart: refactor uart udr write operation outside generic uart write.
avr_timer: changed avr_timer_write_ocr as part of larger avr_timer refactor.

- changed avr_timer_write_ocr code to take pointer of relevant
  	comparator structure rather than its parent timer.

- added _timer_get_comp_ocr which the modified avr_timer_write_ocr
	function uses.

	modified:   simavr/sim/avr_timer.c
	modified:   simavr/sim/avr_timer.h
Merge pull request #56 from bsekisser/avr-timer-comp-write-ocr

avr_timer: changed avr_timer_write_ocr as part of larger avr_timer refac...