Thanks @MagoKimbra.

Fix for #1460.

Seems to work with only one extruder. Can't test this myself with more.

A `z_before` value is passed to probe_pt, but the `retract_z_probe`
function assumes that Z is 0, doesn’t add `current_position[Z_AXIS]` as
other cases do. This may be superfluous, so this is a test, and will be
reverted if it has no effect.

- Fix `prepare_move` function not calling `adjust_delta`
- Add more shorthand for plan_buffer_line.
- Fix wrong `federate` usage, assuming they are all mm/m
- Minor `stepper.cpp` cleanup

- Users prefer `G29 E` to work like `M48 E` so fixed that
- `M48 n` replaced with `M48 P` (or `p`). `n` legacy support
- Shorten some strings to save precious bytes
- Smaller code for 3-point probing

- Fixed a typo causing G28 to home incorrectly
- Added documentation to G28
- Added homeXYZ bools to neaten the code
- Added a note about home_offsets being questionable

cardreader.cpp needs temperature.h for autotempShutdown() when
AUTOTEMP is defined but warns about unused variables.
Unpublished variables by putting them in to temperature.cpp.

and satisfy the compiler about the implicit compare.

therefor in macro ST7920_WRITE_BYTE(a) cast a to uint8_t
to make the compiler happy.

and make use of column 20.

Another fellow here gave me the idea to do it this way

Made my swap commented out so its the option not the default.

This reverts commit 15028e9b.

I made my changes to swap MIN and MAX endstops on the Azteeg X3 Pro the
option rather than the default to fix unexpected reversal.

Updated for the changes that Thinkyhead made before I submitted mine.

I added in the pins into the new board files for the Azteeg X3, X3 Pro,
Printrboard, and Rambo. I'm sure it can be added for others too but
these are the manual specified pins. Just like many things here though,
I can't test for the boards other than the Azteeg X3 Pro. Hopefully it
works smoothly for everyone who happens on this nifty display. :)

- Add some documentation to planner and stepper headers
- Patch up RAMBO pins with undefs
- Add `sync_plan_position` inline to set current XYZE
- Swap indices in `extruder_offset` to fix initialization values

I added the fan pins in here and left them at -1 in configuration_adv.h
and it works fine. Pinned for a 4 extruder from 1-4 and HE5 being the
controller fan, HE6 being the Extruder Auto Fan/Water pump in the Kraken
case, and HE7 being for part cooling fan. Added in descriptions for the
MIN MAX pin swap and for servo motor additions.

- Addressing issue mentioned at #1699

to avoid warnings about unused blink.

Concentrate definitions of variables in dogm_lcd_implementation.h to one place.

Make only local used variable currentfont static.

- Patched up for most included configurations

- Also patch up some warnings

- Fix a bug reading `code_value` for `M503 Sn`
- Hide and remove unused variables