Fix step rate bug (especially for retraction)

Marlin with ATmega1284p sanguino support under Arduino 023

Added the optiboot bootloader, uses only 512kB of FLASH
Includes .hex file is for 20MHz µC Clock and serial speed of 57k6

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=

ATmega644P 16MHz, ATmega1284p 8, 16, 20MHz

Hotend offset handling for multi-extruder machines

Conflicts:
	Marlin/language.h
	Marlin/thermistortables.h

Marlin v1, alignment of the Italian language

Update Marlin/language.h

Update Polish language 	#define MSG_RESUMING "Wznawiam drukowanie"

Add SD-Card change and SD-Card init. for electronics equipped with LCD Display

Update Marlin/ultralcd_implementation_hitachi_HD44780.h

Fix to a bug that I just introduced - sorry. Forgot about offset of string length.

Add SD-Card change and SD-Card init. for reprap electronics without
SD-Chard change detect pin.

Update Marlin/ultralcd_implementation_hitachi_HD44780.h

Use all available characters in narrow LCDs < 20 characters.

Fix to a minor bug with hardcoded LCD_WIDTH that draws edited values outside of the 16 characters width LCDs.

The extruder offset can be specified in the configuration
file or adjusted on the fly using the "M218 T# X# Y#" command.
The EEPROM support is not yet merged in.
The "T#" command can take option "F#" that specifies the feedrate
at which the printing head should be re-positioned. If not
specified the re-positioning move is not preformed immediately,
but the coordinates are adjusted for the printer to properly
position the head when the next movement happens.

Also skip .files and _files with long filenames. I think its better than before. If somebody dislikes it, or wants additional configuration, it can be done in a future step. Thanks, Marius, and nice to have you helping!

Chenged LED_PIN for Melzi boards, added comment about broken versions of...

compile fix: quickStop() needs stepper.h

This reverts commit 01541ee64c.

[default off for now]
syntax: M600  X[pos] Y[pos] Z[relative lift] E[initial retract] L[later retract distance for removal]

if enabled, after a M600, the printer will retract by E, lift by Z, move to XY, retract even more filament.
Oh, and it will display "remove filament" and beep like crazy.

You are then supposed to insert a new filament (other color, e.g.) and click the display to continue.
After having the nozzle cleaned manually, aided by the disabled e-steppers.
After clicking, the printer will then go back the whole shebang, and continue printing with a fancy new color.

Marlin v1, italian MSG_RESUMING and RepRapPro thermistor tables.

Panelolu pin assignment for sanguinololu

Add feature to briefly run the cooling fan at full speed when it first starts.

Finnish language

+ Finnish translation

Add a feature to run the cooling fan at full speed for a small period
(default 100ms) when first starting the fan.  Some fans wont reliably
start spinning at low power, and many fans have issue with the PWM at
low power.  However, once the fan starts spinning it can reliably be
set to a wide range of PWM values.

Always set the FAN PWM value in check_axes_activity() and always use
the value of the active move if a move is active.