Allow `ENABLED`, `DISABLED`, `PIN_EXISTS`, and `BUTTON_EXISTS` to take multiple arguments. Also add:
- Alias `ANY(...)` for `!DISABLED(...)`
- Alias `ANY_PIN(...)` for `PIN_EXISTS(a) || PIN_EXISTS(b) ...`
- Alias `EITHER(A,B)` for `ANY(...)`
- Alias `ALL(...)` and `BOTH(A,B)` for `ENABLED(...)`
- `NONE(...)` for `DISABLED(...)`
- Use `TEST(dm,axis)` to determine directions instead of doing comparisons.
- Remove recomputation of `millimeters` and `delta_mm` since backlash compensation should not affect the distance over which material is extruded.
* Clean up Temperature PID
* Improve EEPROM read/write/validate
* Group `SINGLENOZZLE` saved settings
* Group planner saved settings
* Group filament change saved settings
* Group skew saved settings
* Group `FWRETRACT` saved settings
- Move FWRETRACT to the planner
- Combine leveling, skew, etc. in a single modifier method
- Have kinematic and non-kinematic moves call one planner method
- Allow planner to alter the deceleration phase of the currently executing block.
- Remove BUSY flag, as it is NON ATOMIC to set bits in the Stepper ISR and Planner at the same time.
- Drop `max_jerk` with `JUNCTION_DEVIATION`
- Add `max_e_jerk_factor` for use by `LIN_ADVANCE`
- Recalculate `max_e_jerk_factor` when `junction_deviation_mm` changes
- Fix LCD editing of `junction_deviation_mm`
- Respect axis max acceleration limits instead of forcing a fixed acceleration value.
- The `junction_unit_vec` ensures proper handling of entry and exit speeds even when the axes involved have different limits.