Updated "servo.h" to "Servo.h"

Corrected "servo.h" to "Servo.h" because of the updated filename.

- Add `M111` as a standard option to set the debug level
- Implement `DEBUG_ECHO` in `process_commands`
- Other debug levels (e.g., `DEBUG_DRYRUN`) need more work

- Address issue raised in #1961

Else will throw error:
@:0 B@:0
Error:No thermistors - no temperature
[ERROR] Error:No thermistors - no temperature

when no bed is defined

delete some tabs

Ensure the probe offset will always be included when homing Z.

c'n'p ftw :/

and add some documentation - how to integrate a new font.

Syntax error.

no user will home to 0 with a max endstopp

and removed some tabs.

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.

Corrected wrong order of parameters.

Introduced in commit 697ee2dc and later spread to other files.