Apply `ENABLED` / `DISABLED` macros to files needing only a small
number of changes.

- 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

Included support for BT dongle on AT90USB boards.
Added LCD Shift Register LCD control
Included support for RepRap Clone Wars project board (SAV MKI).