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>

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

Found a couple of unused variables, that I commented.
Tried to solve the program memory warning message, and failed.

Advance (not tested)

Add serial checkRx in stepper ISR.
Copied HardwareSerial to MarlinSerial (Needed for checkRx).

Added simple endstop filter.
Corrected M114 count display.

Merge branch 'Marlin_v1' of https://github.com/ErikZalm/Marlin into Marlin_v1

Conflicts:
	Marlin/Marlin.pde
	Marlin/ultralcd.h

This reverts commit 8bcdb9f5f0.