We can save more and a pile of RAM by eleminating the eqnBVector and
EqnAMatrix arrays next.

* UBL G29 -P3.1 mesh fill with distance-weighted least squares fit.

* Back to original -O0 on G29 for now.

* Restore LSF functionality

Some of the typo's persisted...   Hopefully this gets them all fixed.

* Restore user's expectations of how G28 should behave

* Allow Nozzle size control with ornery host programs

UBL Clean up.

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

Also...   The memory corruption issue may be fixed.   The GCC compiler
was inlining static functions and this caused the G29() stack frame to
become much larger than the AVR could handle.

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'.