Includes:
  *firmware version / branch / date.
  *extruder count
  *board information (name, serial details, power supply type)
  *thermistors (names, min/max temperatures)
  *printer statistics (PRINTCOUNTER details)

Thanks to @thinkyhead for contributions.

Following up on #3231

Keep "astyled" reformatting

- `SD_DETECT_PIN` replaces `SDCARDDETECT`
- `SD_DETECT_INVERTED` replaces `SDCARDDETECTINVERTED`
- Revise the description of `SD_DETECT_INVERTED`
- Add a note about the override of `SD_DETECT_INVERTED` in
`Conditionals.h`

- Rename the pin so it can be tested with `PIN_EXISTS`
- Fix some incorrect tests for `SDCARDDETECT`

For consistency with other pins, allowing use of `PIN_EXISTS` macro.

Apply `ENABLED` / `DISABLED` / `HAS_SERVOS` macros to pins files.

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

The encrot values are used in only one place, and don’t vary, so remove
redundant references.

Hopefully this is helpful to organization and future expansion….

Hopefully this is helpful to organization and future expansion….

Hopefully this is helpful to organization and future expansion….