See #4316

Better BLTOUCH support

Mea culpa!

Handle nonlinear bed-leveling in Planner

This is in advance of moving non-linear bed leveling to the planner
class.

Some comments, const args, debug output tweaks

Allow non-square Auto Bed Leveling grid

Standardize code_value_bool

Tweak some german language strings

Remove SCARA axis_scaling

Enable M0/M1 with Emergency Parser

Change some string to get a better wording in german

Use simplified Z correction in G29 when possible

Additional documentation of Configuration.h

Update language_de.h

Fixing Pin Definition Files to Define USBCON