Added support for BQ ZUM Mega 3D board and stock Hephestos 2 thermistor.

//100k 0603 SMD Vishay NTCS0603E3104FXT (4.7k pullup) (calibrated for Makibox hot bed)

Caveat Emptor —- 
I’m not sure that this really makes sense,
but why keep someone from using it?

Keep "astyled" reformatting

Added a second sensor and made them configurable.

Am I the only one who always need to change the thermistortable.h to add
a dummy table??
Ok, it is done. Just set the thermistor to 999 and it will always read
25C. Great for Testing or Development purposes.

Wrong number on line 627 > i change number "12" by the correct number "13"
Soory

Add another thermistor table (13),it's a cartridge thermistor up to +300°C,use with Hotend "Simple ONE" & "All In ONE"

Thx

Add another thermistor table,use with hotend "Simple ONE" & "All in ONE"

sorry for that

it's caracteristics are :

R25℃ ;100KΩ±1%

B Value(R25/50℃)：3990K 1%
Dissipation Factor(mW/℃)：1.1~1.6 In still Air
Thermal Time Constant(S)：10~17 In Still Air
Operating temperature range：  (-50~+260°C)
Dimension：  1.8mm Dia X4.1mm
Lead Length  ：30mm

This table was found on the following blogs:
http://cae2100.wordpress.com/2014/03/08/beta3950-thermistor-table-for-marlin/

and

http://microfabricator.com/articles/view/id/531ad7e59a/beta-3950-thermistor-table-for-marlin

Generated with createTemperatureLookup.py. The old table crapped out at
270C, which was a problem for polycarbonate.

This reverts commit 3682d9bd5b.

- 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

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

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