Split ramps1.3 in Sprinter like config and multiextruder config.

Added M221 extuder multiply factor.

I find that the PID routine works better when the cooling fan is switched on
at the beginning of a warm up routine.  Otherwise when you enable the fan
just before a print, you have a delay as the PIDre-adjusts.

This should also be safer as most cooling fans are directed at the hot -ends
thermal barrier!

Instead of a single pre-heat, now there is pre-heat ABS and PLA options
Added defines to the configuration file to adjust preheat temperatures for both

Updated the Xsteps ... settings via the LCD menu

Signed-off-by: Blair Thompson <mail@justblair.co.uk>

next try for manual axis movement

Added a workaround.  Ramps SD card does not have sdcarddetect.  My temporary solution is to add a momentary swtich
that pulls down the SDCARDDETECT pin and mimicking the pull and reinsert ofa a SD card

replace $ARDUINO_HOME/hardware/tools/avr/etc/arduino.conf with this file

Conflicts:
	Marlin/Configuration.h

Simplified stepper inactive time

Updated SERIAL define to MYSERIAL, because Arduino 1.0 defines SERIAL as 0.

if (millimeters_of_travel == 0.0) => if (millimeters_of_travel < 0.001)
(thanks mooselake)