added suicide pin for a power supply to the arduino that is only active if the arduino is holding high for an output.

 arduino-0023/hardware/arduino/cores/arduino/wiring.h
this is necessary if the avr libraries are recent, but arduino is old. Alternative: newer arduino

advance and ultipanel not any more in default config

This reverts commit 651cde8b.

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

heating up santity, formarly knows as "watchdog", but renamed due to the existance of the real watchdog, works now.

Fix M201 not saving settings in all places, so the changes did not get written into EEPROM

added a partial release option to "m84" aka "stepper release". If you do tiny layers, you might want to keep the z-axis powered to not loose height positioning after homeing.

fixed the st_synchronize. it would have continued if there is only the last move of the buffer being stepped.