This is the easiest way to make button pin testing consistent without
renaming all the button pins. Just make a macro especially for testing
if button pins are set, since they are named consistently in the pins
files.

Fixed backlight for PCF8575.

Signed-off-by: Christian Inci <chris.pcguy.inci@gmail.com>

Following up on #3231

Alternative fix to #3149

lcd_erase_line() is called with argument, but the argument is ignored by lcd_erase_line().

Renamed `WARN_REDUCED_ACCURACY` to `DISABLE_REDUCED_ACCURACY_WARNING`

Changed the condition for blinking from
```
#if ENABLED(WARN_REDUCED_ACCURACY)
```
to
```
#if DISABLED(DISABLE_REDUCED_ACCURACY_WARNING)
```

Exactly the same - copy/paste.

Introduce additional variable axis_homed to replace axix_known_position
when the coordinate display should indicate the axis is not homed.
This is to distinguish between "not homed" and "inexact position possible
because stepper was disabled".

# Conflicts:
#	Marlin/ultralcd_implementation_hitachi_HD44780.h
solved

Implement and test blinking for char-lcds

# Conflicts:
#	Marlin/ultralcd_implementation_hitachi_HD44780.h
solved

The domain is gone and doesn’t redirect, so for now show no URL on the boot screen.

Fix status LEDs update when reinitializing the display

By using the regular update function during init.

Fixing #2683

According to #123 negative values for XY at or below -100 are displaying incorrectly, dropping the first digit. Deltas can easily have XY values in this range. This PR adds a function to display floats/ints formatted like `_123`, `-123`, `_-12`, or `__-1` as appropriate and applies it to the XY coordinates on Hitachi displays. It also moves the Z value to the right to be consistent with the XY formatting.

Keep "astyled" reformatting

Centred the logo for 16x4 and 20 x4.
Moved version to the bottom line
Code shrink to 704 bytes.

Uses about 488 byte of progmem and 32 byte of RAM.
For that configurable.

Apply `ENABLED` / `DISABLED` macros to LCD-related files.

Also clean up some trailing spaces in a few other sources

- Also show 2 digits past decimal for Z on DOGM

to avoid errors in Marlin_main.cpp. #1860

In the include tree of Marlin_main.cpp the decision between the display types is not made.
To include the right LCD_STR_* ether 'dogm_lcd_implementation.h' or 'ultralcd_implementation_hitachi_HD44780.h' with all their code.
A 'dogm_lcd_implementation.h.h' would be a curiosity.
So i moved both of the definition blocks to conditionals.h

On the long term it could make sense to use the same numbering for the u8glib and the hitachi symbols.