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.
* relocated ubl state to config. store:
* removed a number of ubl state variables and padding which were largely unused - saved 58 bytes of both SRAM and EEPROM;
* modified ubl sanity_check - no longer checks removed state variables that were otherwise unused, where checking didn't seem to accomplish anything, ultimately;
* removed pre_initialized state, saving 64 bytes of SRAM;
* removed automatic saving of UBL state after UBL activation/deactivation;
* consolidated multiple GRID_MAX_POINTS_X/Y to 'Global Leveling' section of EEPROM;
* minor update to G29 Sx notes/instructions;
* renamed mesh load and save parameter to 'slot' from 'm' for clarity;
