Add an item to the LCD menu that applies the current axis position to
the “add_homeing” offset.

The serial protocol has to stay machine readable, without having
to cope with a ton of different human language variants. So
just leave it at the original english version.

Should fix ErikZalm/Marlin#1052

FW retraction is extended onto swap retraction invoked by 'G10 S1'.
Bookkeeping of the retract state of all extruders allows for having one
extruder fw standard retracted while another extruder is swap retracted.
An LCD menu item for the swap retract and recover length was added.

Added:
* new language (Basque-Euskera)
* some minor corrections for Spanish
* added 2 new constants for every language (required for a minor change
I am preparing to ultralcd.cpp)

Updated to latest version.

Added catalan language

Preheat LCD menus base on code by D-Base

Extension of M221, Tune menu

Firmware retraction now stores the retract and recover speeds in mm/s
instead of mm/min. This makes it match the units of the maximum
feedrate, and fixes problems with modifying the value via LCD control
panel. From gcode, the values are still taken in mm/min to match the
units of G1 and similar, and they are converted to mm/s before they are
stored.

I also lowered the default retract feedrate to make it less likely to
cause problems for geared extruders when the user hasn’t bothered to
set a reasonable maximum feedrate, though users should be setting both
of these values to suit their hardware.

- Fixed Few finnish transalations
- Removed duplicate contrast define

This reverts commit 6f76066ab3, reversing
changes made to e1ae7952eb.

Updated Polish translations.

Recommended for those who are using the Z Probe for Z Homing (as
Z-Endstop)

This feature has two changes:

1) Allow user to choose where the Z Probe will touch the bed when homing
all axis together (G28) by setting below defines:

Z_SAFE_HOMING_X_POINT
Z_SAFE_HOMING_Y_POINT

2) Prevents the user to perform Z Axis Homing when the Z Probe is
outsite bed.

Some strings still need translation, but at least everything compiles.

I update the spanish Messages, now this compile for spanish language.

Also cosmetic comment changes and spelling corrections in printed
messages

Add new 'callback' edit-menu types that call a function after the edit is done. Use this to display and edit Ki and Kd correctly (removing the scaling first and reapplying it after). Also use it to reset maximum stepwise acceleration rates, after updating mm/s^2 rates via menus. (Previously, changes did nothing to affect planner unless saved back to EEPROM, and the machine reset).

Add calls to updatePID() so that PID loop uses updated values whether set by gcode (it already did this), or by restoring defaults, or loading from EEPROM (it didn't do those last two). Similarly, update the maximum step/s^2 accel rates when the mm/s^2 values are changed - whether by menu edits, restore defaults, or EEPROM read.

Refactor the acceleration rate update logic, and the PID scaling logic, into new functions that can be called from wherever, including the callbacks.

Add menu items to allow the z jerk and e jerk to be viewed/edited in the Control->Motion menu, as per xy jerk.

Conflicts:
	Marlin/language.h