Fix thermal runaway when nonexistent bed temp is set

Configurable delay for BLTouch servo emulation

G38 bug fix, made double touch optional & reverted to Z_MIN_PROBE

Fix LCD preheat menus

Add .gitattributes to normalize line endings

Patch MarlinSerial to match up with 32-bit version

Patching up UBL, vetting recent commits

Fix broken auto#.g, some other regressions

Add PROBE_MANUALLY — ABL without a probe

Further adjustments to UBL code