Improved MANUAL_[XYZ]_HOME_POS

No need for `MANUAL_HOME_POSITIONS`. Just set each one as-needed to
override the automatic behavior.

Fix output of heater states

Switch Sd2CardLib to fastio

A little cleanup at speaker.h

Prevent compiling with old Arduino sooner

Fix DELTA speed calculation

Fix for R.D.F.G.S.C. with MEGATRONICS 3 board

The support for reprapworld LCD boke the code for the REPRAP_DISCOUNT_FULL_GRAPHIC_SMART_CONTROLLER. See Full Grapics Display does not work any more after #4408  #4439

DELTA should ignore Z_SAFE_HOMING

Allow Z_SAFE_HOMING without a probe

Replace all fastDigitalRead/Write() with READ/WRITE()

Define SCK_PIN, MISO_PIN, MOSI_PIN in pins.h if not already defined in the pins_*.h files.

Remove these conditional pin definitions from the pin-files. They are now always defined.

Define separate sets of SPI-pins for AT90USB with and without Teensy support in fastio.h.
Likely this was the main reason for all that confusion about the AT90USB-SPI pins.

Allow zero raise for deploy/stow

[LANGUAGE] Update Czech (Info screen strings)

Split up Conditionals.h into two files

Remove MSG_PRINT_TIME from languages

Rather than include twice, which is tricky but may confuse

Followup #4402 fixing 3-point leveling

Move HAS_DIGIPOTSS to Conditionals.h

Clean up Transfer Buffer Size comment