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.

・Update forgotten example configurations

This is an update of MarlinDev PR #196.

G20/21: support for switching input units between millimeters and
inches.
M149: support for changing input temperature units.

In support of these changes, code_value() and code_value_short() are
replaced with an array of functions which handle converting to the
proper types and/or units.

Saves about 2669 bytes when deactivated. (About 1% for a AT2560, about __4%__ for a AT644!)

Fix for PR #3526(Configuration.h LCD & SDCard section rewrite)

It removes duplicated BQ_LCD_SMART_CONTROLLER.

Some clean-up for example configuration files

Follow-up and fix the PR #3253(Make the Autotune item(s) in the LCD menu optional):
・Update forgotten file(Felix/Configuration_DUAL.h)

Follow-up the PR #3526(Configuration.h LCD & SDCard section rewrite):
・Add section of RigidBot Panel to RepRapWorld/Megatronics/Configuration.h

Follow-up the PR #3576(Z Safe Homing for all):
・Adjust spacing

Follow-up and fix the PR #3625(Print job statistics):
・Update forgotten file(Felix/Configuration_DUAL.h)
・Remove ambiguous character "f" in top of RigidBot/Configuration.h