Little update

* UltiMachine Archim2 support

* SPI gets included by the library

* Invert TMC2130 diag pin state

* Clean up Archim2 pins

* Update Archim2 config

* FAN2 -> FAN1

* Cleanup

* Add brief Archim installation instructions

* Bring pins into compliance

* Update 1.0 SD Detect pin for 1.1

* Update Configuration.h

* Update pins_ARCHIM2.h

Following up on #3231

- Add BIT and TEST macros
- Add _APPLY_ macros to stepper.cpp to help with consolidation
- Consolidate code in stepper.cpp using macros
- Apply standards in stepper.cpp
- Use >= 0 instead of > -1 as a better semantic
- Replace DUAL_Y_CARRIAGE with Y_DUAL_STEPPER_DRIVERS

- Both TMC, L6470 and pin-driven drivers work.
- All can be mixed and matched as needed.

Add digipot i2c control for MCP4451
Allow M907 to set i2c digipot currents in amps
Fix Makefile to allow Azteeg motherboards
Fix Makefile to allow Wire libraries only
Add beeper pin for Azteeg X3 Pro

Check the Readme for instruction how to enable and configure the feature

Diffed and merged, preserving my updates

Reviert previous change of #if BLAH_PIN > 0 to #if defined(BLAH_PIN) &&
BLAH_PIN > -1. Unfortunately some times pin 0 is used. For my sins I've
gone through and replaced all unsafe checks of #if BLAH_PIN > -1 with
the safe version.

The new version of the library means that PANELOLU no longer needs to be
defined in LiquidTWI.h (the library file can be used as is) and the new
version of the library also enables the buzzer on the Panucatt VIKI
panel.

Refactor configuration to try to make items clearer (what defines a
panel vs what is user changeable).

Also fix compile time check in Marlin.pde

This includes refactoring the buttons code to remove a large amount of
non-pin dependent duplication from pins.h.