* Group status methods, share reset_status with Extensible UI
* Move common DOGM code to headers

* Encapsulate common LCD code in a singleton
* Depend more UBL code on UBL_DEVEL_DEBUGGING
  - Since most users don't need the debugging on at all times, this helps reduce the default build size for UBL by over 2K, a little closer to fitting on 128K boards.

- Changed type of integer used for feedrate percentage from uint8_t to uint16_t.

- Show units on lightweight status screen.
- Fixed progress bar so it works with M73

- This status screen uses the ST7920 character generator to greatly
  reduce SPI traffic and MCU load when updating the status screen.

- Has been tested with the RepRapDiscount Full Graphics Smart Controller
  but should work with any LCD that uses an ST7920 or fully compatible
  controller.

- Also deleted old implementation files which had been renamed.