Added Witbox printer changes:

*  M700 - Level plate script used on Witbox printer interface. Take 3 points to adjust the bed manually.
*  M701 - Load filament script used on Witbox printer interface. This helps to load the filament and extrude automatically
*  M702 - Unload filament script used on Witbox printer interface.This helps to unload the filament and extrude and then retract automatically
*  MOTHERBOARD 36: for use dual extrusion with cooling fan on RAMPS(Extruder0, Fan, Estruder1)
*  Auto filament change on CHANGEFILAMENT feature. Now you can activate this option that load the filament after retract it.
*  Witbox user friendly interface, for people unfamiliar with the technicalities