- 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

- Make the default LCD click sound more pleasant
- Fix warnings about bed temperature runaway

This rolls back to commit 06f767d608.

- Some messages should not expire with `PROGRESS_MSG_EXPIRE`.
- Simplify conditional for progress bar with sanity checks.
- Rename `messageTick` to `expireStatusMillis` and make it the expire
time.

Fix for #1460.

Seems to work with only one extruder. Can't test this myself with more.

- Patched up for most included configurations

- Increase the probe offset range to -20…20
- Apply the range limits to the menu item