The PrintrBoard Rev F utilizes a mcp4728 DAC to set motor current. Printrbot's implementation utilizes 2 new M-codes to set and write the DAC settings to the DAC EEPROM: `M909` (Read DAC) and `M910` (Write DAC). `M907` is re-used to set value, `M908` for direct control.

The Pins file for the RevF board is included.

Use const parameters in lcd_implementation_drawedit (etc.)

Alternative fix to #3149

Support for multiple PWM fans

Addressing issue #2767

Use a serial line buffer to prevent queue corruption

Implement BABYSTEPPING for COREXY and COREXZ

Provide feedback to hosts when busy

If Marlin is blocking the serial input or command queue for any length
of time (for example more than 2 seconds), it needs to send a message
to serial out to inform the host that it is busy. Marlin should only
send these messages out when busy, and preferably not when trying to
print formatted output.

follow-up the PR #3114

follow-up the commit d56c6af24e

suppress warnings

Option to reverse the click-wheel direction in menus

Fix initial extruder direction for second/third/fourth extruder if they run inverted to the first

Fix CardReader::lsDive()

fixes MarlinFirmware/Marlin#3144 and MarlinFirmware/Marlin#3083

Use variable in lcd_erase_line()

Fix for #3160 MESH_BED_LEVELING broke correct G1 movement in Z

Promote STRINGIFY to macros.h

Support "true" and "false" in the ENABLED macro

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

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

Addition to #3140

Uptades the pt-br translation

Additional macro wrapping, patches for #3140

Wrap macros to prevent bad expansions

Use local variable in recalc_delta_settings()

diagonal_rod hadn't been used anywhere.

Extend stack_overflow_protection for lcd_move_e and _lcd_level_bed

Extend stack_overflow_protection for lcd_move_e() and _lcd_level_bed() with
a refined method of 3050.