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

Conflicts:
	Marlin/temperature.h

get rid of indirect ringbuffer calls, made some inlines, removed virtual and streaming class requirements.

(When using the lower and upper adc input bank)

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

first naive attempt to have a offset in the homeing procedure. Does not enable to move into regions not allowed by endstops.