Example Configuration.h files are not updated yet.   You need to cross
your settings over to the default Configuration.h file in the \Marlin
directory.   (UBL_G26_MESH_VALIDATION enablement has moved to a new
location in the file.)

* auto tune calibration parameters

* solve warnings

* Tweaks to formatting

* review Thinkyhead

* Error

set_destination_to_current() changed to set_destination_from_current()

set_current_to_destination() changed to set_current_from_destination()

* matrix names update

* symplified names

* new angle normalization

* ABC

* axis

* least squares

* recalc_delta_settings

* endstop_adj

* 0p

* bug

Fix regression in #7428

===============================================

also an issue with ubl_motion.cpp

* Change all direct changes of ubl.state.active to
  set_bed_leveling_enabled() which handles apply/unapply
  leveling to maintain current_position consistency.

Fix invalidation of UBL mesh to invalid unreachable
  mesh points as well (delta corners).

Fix UBL_DELTA unapply_leveling logic and when
it gets applied, including fade_height changes.

Add optional M114 D for detailed position information,
disabled from compilation by default (M114_DETAIL).

* UBL_DELTA raw and inline kinematics

* UBL planner fall through fix

* consistent variable names

* Cleanup orphaned code and whitespace changes.
Use _O2.

* compile warnings cleanup

* Remove redundant #ifdef condition

Followup to #6827

Fix undefined DELTA_PROBEABLE_RADIUS for UBL_DELTA

* UBL_DELTA post merge cleanup:
   fix fade_height, lost during some previous merge
   fix float cx,cy which are not const
   move repeated z_cxcy calc line inside loop
   style fixes and comment fixes/alignment

* Update ubl_motion.cpp

remove unnecessary parentheses

* Update Conditionals_post.h

Change name of define to more accurate meaning:
UBL_GRANULAR_SEGMENTATION_FOR_CARTESIAN
which is not and should not be the default for cartesians with UBL.

Also clean up ubl_motion.cpp debug info and fix declaration of cx & cy

UBL on Delta's....     Should be close!    Should not affect any Cartesian printer.

- Fix bug in ubl_line_to_destination
- Improve/fix output of some ubl.h functions

I think I forgot to Sync before I committed last time.   Some UBL
changes did not stick.

Also, update the gMax configuaration.h file so other than unique numbers
and settings, it exactly matches the default configuration.h file.

* Fix Horizontal and Vertical optimization bug.

And drastically reduce the debug code foot print....

* Yeah Baby!

The debug print is going A - OK !

add BLTouch-related messages in english and (rusty) french;
add missing endstops.h in ultralcd.cpp;
fix misc. compiler warnings;
fix lsf_reset - ZERO macro can't handle a pointer as it would only memset the size of the pointer, not the size of the entire struct

* Correct over optimization of pre-initialized variables

NEAR_ZERO() works most of the time...  But it leaves corner cases
uncovered.  We need to explicitly check if these variables are +/-
infinity.

* Correct over optimization of pre-initialized variables

fix maximum mesh_index_ array size at 16 (15+1);

Pretty much...  The code is in place.  Still more work to do.    But it
has a lot of hooks and variables in other code, so commit and merge
before I pick up a million 'Conflicts'.