V1.4 moves thermistor power to the always-on 5v line.
The BOGUS_TEMPERATURE_FAILSAFE_OVERRIDE is no longer
needed on this board.  Add a new motherboard type to
support this feature.

The code to ignore the "bad thermistor reading failsafe"
suicide function depends on the existing of the PS_ON pin
feature.  But in some boards this shouldn't be the case
Fix this by adding an explicit definition to make our
intentions more clear and separable.

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

that pulls down the SDCARDDETECT pin and mimicking the pull and reinsert ofa a SD card

- Added support for ATMega1284

Needs some work to remove the blocking in read max6675.

Added late z enable. (blddk request)
Only calculate look ahead if >2 moves in buffer.
Removed some FORCE_INLINE to save memory.

Signed-off-by: Erik van der Zalm <erik@vdzalm.eu>

advance and ultipanel not any more in default config

Soft PWM. (Sanguinololu can also have PID temperature control)
Interrupt save WRITE for addresses > 0x0FF

- The temperature control is pretty much complete
  (not sure what to do w/ autotemp though)
  Changed the pins assignment to clearly separate bed and extruder heaters
  and temp sensors, changed a bit how termistor tables are handled.
- The steppers control is rudimentary
  (only chanages what pins it uses depending on the active_extruder var,
   but that's enough for switching extruder in the start.gcode in the
   the profiles)
- Tested only w/ RAMPS 1.4