Add additional Sanguino bard versions to boards.txt

ATmega644P 16MHz, ATmega1284p 8, 16, 20MHz
Switched to Sanguino 0023r4

This is the actual Sanguino release for Arduino 023.
It has full ATmega1284p support.

Reference:
https://code.google.com/p/sanguino/downloads/detail?name=Sanguino-0023r4.zip&can=2&q=
Add bootloader files for ATmega1284/Sanguino

Added the optiboot bootloader, uses only 512kB of FLASH
Includes .hex file is for 20MHz µC Clock and serial speed of 57k6
Merge pull request #408 from STB3/Marlin_with_ATmega1284p_Sanguino_on_023_support

Marlin with ATmega1284p sanguino support under Arduino 023
fixed merge conflict
Replaced corrupted language.h file on local PC with current from ErikZalm/Marlin
Add Motherboard variant 64 - STB V1.1

Definition for the graphic LCD are already in it, they will not harm the
configuration as they are only defined constants
Add pins for Motherboard variant 64

These definition contain also the definition for the graphics LCD.
regenerated thermistor table 7

Generated with createTemperatureLookup.py. The old table crapped out at
270C, which was a problem for polycarbonate.
missing comma in last commit
Merge pull request #1 from illuminarti/Fix_E_Speed

Fix step rate bug (especially for retraction)
Add command M928 to enable logging to file of received gcode commands
Clean up tab/whitespace from last commit
Merge pull request #411 from STB3/Marlin_w_STB_Board_support

Add STB board support to Marlin (next step towards graphic LCD implementation)
Add Motherboard variant 64 - STB V1.1

Definition for the graphic LCD are already in it, they will not harm the
configuration as they are only defined constants
Add pins for Motherboard variant 64

These definition contain also the definition for the graphics LCD.
Merge pull request #1 from illuminarti/Fix_E_Speed

Fix step rate bug (especially for retraction)
Adding Maker's Tool Works heated bed thermistor
Removed umwanted HTML code ath the end of the file

Sorry for that. This does not lead to compile errors. I removed the
unwanted code to make it clean.
Add missing LF at the end of the file