Marlin with ATmega1284p sanguino support under Arduino 023

Updated the Sanguino files under ArduinoAddons/Arduino_0.XX
This is the latest version from https://code.google.com/p/sanguino which is available for Arduino 023. It adds full ATmega1284p support.
I included the optiboot bootlader https://code.google.com/p/optiboot/ and added the .hex file compiled for the ATmega1284P 20MHz 57k6 baud rate speed. Because the original Sanguino files do not have a ATmega1284P bootloader.

This is the first part of modifications necessary for the graphics lcd support which is using a modified Sanguino hardware. --> see pull request #399 which contains all necessary changes in one request.