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.

added M503 to display eeprom storage, and renamed eeprom routings. This version is compatible with the qtmarlin eeprom-tab.

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

Advance (not tested)

Might be replaced by something more clever, e.g. by erik, and does not yet support the second extruder or the bed.
its kind of not so cool, because you need 6 more ints.
Maybe isheating() should use the degrees directly, as it is not used in time-critical anyways.
Then it would be much easier. to have the offsets without additional variables.

made it compile if arduino decides to include files in a differnt order. DEC HEX and stuff now defined in MarlinSerial.h