Fix endstop pins for Printrboard

Move the Arduino related stuff out of the Marlin tree, as they are not directly related to Marlin functionality but addons for the Arduino IDE. Also split up the addons for pre 1.0.0 Arduino and post 1.0.0 Arduino.

Use the disable macros on initialization. Which fixes a bug when there is no pin defined for stepper enabled (motherboard 4)

Add Printrboard and Brainwave to pins.h and fastio.h

Big temperature code update. No longer converts back and forwards between temperature and raw sample value. Reducing complexity, removing code. Also named some variables better. While keeping the safety intact and functionality the same.

Stop redefining MOTHERBOARD and #define AT90USB instead. Also put #ifndef AT90USB around the HardwareSerial_h trick, so now Printrboard / Brainwave support compiles on Arduino 1.0.2 as well.

Add support for Printrboard (from https://github.com/lincomatic/Marlin) and Brainwave (from https://github.com/metrix/Sprinter).

Small makefile change, posibility to add defines on the commandline, and fix compiling with watchdog enabled when using the Makefile.

Fix the WATCHPERIOD implementation. It did not work correctly in a multi extruder setup, it did not work after 32 seconds after startup (int16 used as millies timestamp). And it did not work if you gave an M104 or M109 when the target was already around the target setpoint. So on average, it did not work at all. The new implementation should be robust in detecting a failure to heat up.

The Partial release message (which does not really tell you anything) overwrites the final print time on the LCD, which is a real shame. So I removed the message.

The Partial release message (which does not really tell you anything) overwrites the final print time on the LCD, which is a real shame. So I removed the message.

Changed the naming of some LCD functions, so the names match better what the function does. Also moved around some prototypes for general cleanup.

Some minor changes on code style. And a bugfix where the counters for positioning in the stepper where wrong depending on compiler settings. (Caused strange values to reported back with M114 and endstop triggers). Also fixed compiling with FWRETRACT enabled.

Fix for keypad

Some fixes in the Makefile to support Arduino 1.0.0 or higher and added the Rambo. Still needs some more work for the different arduino hardware variants.