Addressing #2879. The M115 report should display `MACHINE_UUID` but it
always displays `UUID`.

Addressing #3085. If the target_temperature is set directly it never invokes or disables the timer set in `start_watching_heater`, so after _stopping a print_ or turning off _all heaters_ you could get a “Heating failed” error.

Move step macros to stepper_indirection.h

Reduce code in stepper.cpp with some macros

Expected behavior: After editing a value the menu should return to the
previous place with the edited item selected.
Actual behavior: Either the top (back) item from the previous screen is
selected, or the menu jumps up another level.
Solution: Pass the correct arguments to `lcd_goto_menu` on click when
editing a value.

Z_RAISE_BEFORE_HOMING -> MIN_Z_HEIGHT_FOR_HOMING

rebased
corrected spelling
changed to #elif for error

Still with MIN_Z_HEIGHT_FOR_HOMING but con be done with (folder wide) search-replace when we have a better name.

M110 and M29 rework

Drop obsolete test for leading "N"

update example configurations

Add 'ok' output for G29 actually closing the file.
Handle M110 when received without linenumber/checksumm.

update old comments
update or delete deprecated definitions
complement forgotten updates
adjust spacing
some cosmetic changes

Bugfix: G28 was lifting Z-axis multiple times

Add Watchdog timer reset in kill()

Update name of st_get_axis_position_mm in stepper.h

Related to MarlinFirmware/MarlinDev#270

See: https://github.com/Ultimaker/Marlin/pull/7

As suggested by @max-pau in #3073 - #3074

files.

This changes have being discussed at MarlinFirmware/Marlin#2849.