replace extruder_multiply with extruder_multiplier
like feedrate_multiplier or volumetric_multiplier

To avoid double definitions.
I prefer to read N for Number not for Nozzle.

to warrant watching is set or reset.

Make setTargetBed() in _lcd_preheat() dependant of TEMP_SENSOR_BED.
Use disable_all_heaters() in lcd_cooldown() and abort_on_endstop_hit.

Fixed a couple defines that were not changed or commented out.

Moved SDCARDDETECTINVERTED and SDSLOW to Conditionals.h.
Added U8GLIB_LM6059_AF to define display specific actions.
Added reminder to compile in u8glib

Rename of define to avoid confusion between the controller and the
display which had similar names.

Added support for new display type

- Also move audio feedback into the command
- Added shorthand for `lcd_buzz` availability

- Add “Level Bed” menu item for auto bed leveling
- Hide the option if homing has not been done yet
- Arrange the Prepare submenu more logically (?)
- Add documentation comments, some white-space
- Apply some coding standards here and there
- Move old encoder multiplier debug option to `ultralcd.cpp`

With these changes the output of `M503 S0` is all you need to restore
the EEPROM. Building on this it is straightforward to save and restore
the EEPROM state using the SD card or external GCode file.

- Added `M145` to set “heatup states” for the LCD menu
- Added `M420` to toggle Mesh Bed Leveling
- Added `M421` to set a single Mesh coordinate
- Extended `Config_PrintSettings` with added M codes
- Cleaned up some comments here and there

- Address issue raised in #1961

Centralised beep code to lcd_buzz().
From gcode_M300() and lcd_quick_feedback().

Enforced max. duration for M300 to 5 seconds.

Corrected description in 'Configuration.h'

LCD_FEEDBACK_FREQUENCY_HZ 0 gives now a silent delay of
LCD_FEEDBACK_FREQUENCY_DURATION_MS.

lcdDrawUpdate = 2 helped a lot!

- MENU_ITEM causes lcd_quick_feedback to be called, so only those calls
to `lcd_goto_menu` outside of the `MENU_ITEM` macro need to set the
`feedback` flag when calling `lcd_goto_menu`.

- Use `line_to_current` in place of `plan_buffer_line`

where the hardware is available.
Fix for #1873

The other two devices we use in u8glib have more than only dummy code.
Checked this in the library code.

Squished #1849

Because we now can use utf8 with up to 3 bytes per symbol,
lcd_status_message[] must be 3*LCD_WIDTH wide.
Filling up the message, or cutting to length, are fixed to.

Fix for #1832 about at the end.

In 'if (encoderPastThreshold || LCD_CLICKED)' lcdDrawUpdate was not set.

'lcd_status_update_delay'-loop was not effective in  function
lcd_status_screen().
The loop prevented the update of the status screen but not the displays
update.
Shifted the loop into lcd_update().

This reverts commit 6361404b91.

Shifted condition should still be in.

Result see: https://youtu.be/AEnBzdu9_tk
Dot is moving not so fast -> less executed loops.

Result see: https://www.youtube.com/watch?v=tdu7J0i-c4g
Loop is executed several times per display update.

* Use "G29 S3 Xn Yn Zn.nn" to modify bad probed point manually
* Changed manual Z steps from 0.05 to 0.025 and made brought it to Configuration.h