Fix Z_DUAL_ENDSTOPS with Z MIN Homing

Explain that Z_PROBE_*_HEIGHT options are nozzle-relative

Within Marlin, maintain most feed rates in mm/s

Remove premature int-cast from MBL cell index methods

Save bytes for custom chars (Hitachi LCD)

Repair SPI-pins, some other pins

for travis builds.

SCK_PIN can't be defined as DIO[number] they mus be defined as pure number.
So rebuilding the structure of fastio.h in pins.h.

Make Allen Key Probe stow

by switching off the tests for the probe before the stow move.

Repair-language.de

Patch up some flaws here and there

Move tests for old symbols to the top of sanity check

Added / Update language_de.h

Z-Height options replace Z-Raise options

Added german translation for MSG_INFO_PRINT_LONGEST and  MSG_INFO_PRINT_FILAMENT.
MSG_HEATING_COMPLETE changed from "Aufgeheizt" to "Extr. aufgeheizt"
MSG_HEATING changed from "Aufheizen" to "Extr. aufheizen"

Update of Galician language

Update August

Define Z_MIN_PROBE_PIN always, allowing override

Only report finished prints longer than 1 min

Prevent the 'tone(f,d)' function from being interrupted