Following up on #3231

If comparison between signed char(-128 ~ +127) and DIR_NAME_DELETED(uint8_t const 0XE5, it's +229),
it makes incorrect result.

Instead of changing SDEXTRASLOW variable to a slower speed,  the new
SDULTRASLOW is used for rigidbot panel.

Instead of changing SDEXTRASLOW variable to a slower speed,  the new
SDULTRASLOW is used for rigidbot panel.

Keep "astyled" reformatting

Add SDEXTRASLOW which runs the SD card at SPI_QUARTER_SPEED. Quarter speed is needed for RIGIDBOT_PANEL

PR#2572 Changed this because of faulty Boolean Logic

NOT(A OR (NOT B) OR (NOT C)) !=

(NOT A) AND ((NOT B) OR C))


Besides, the compiler should be smart enough to
optimize this without help from the programmer

Apply `ENABLED` / `DISABLED` macros to files needing only a small
number of changes.

Makes the output on the LCD adjustable.

When one hit "Stop Print" option in LCD menu, the command buffer was not
cleared. The printer keep moving until the buffer has been emptied.
Actually I could not clear the command buffer as well.. I don't know
why, it doesnt work as expected.
I need to implement a routine inside Stepper ISR to handle such
situation.

- Apply standards to cardreader.*
- Fix minor issues with cardreader.cpp
- Apply standards to some other stale regions

Introduced lcd_strlen() and lcd_strlen_P().
Replaced the old functions where necessary.
Reworked language_ru.h.

Speeded up test for zero length string in cardreader.cpp

Replace instances of the number 13 with FILENAME_LENGTH where
appropriate.

Replace instances of the number 13 with FILENAME_LENGTH where
appropriate.