DAC_STEPPER_DFLT wasn't changed to DAC_MOTOR_CURRENT_DEFAULT in all
places on PR #6124

# This is the 1st commit message:

MCP4728 consistency & fix ultralcd.cpp

The MCP4728 DAC controls the stepper motor current strenth on the
PRINTRBOARD Rev F and RIGIDBOARD V2 boards.

PR #5792 on 9 FEB 2017 implemented default drive percentages but only on
the RIGIDBOARD V2.

This change moves the default settings to Configuration_adv.h.

Also, ultralcd.cpp won't compile because of a type def conflict.
Changed it to match the one in stepper_dac.cpp

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reword stepper curent section for clarity

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change name & improve comments

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changed name from A4JP to SCOOVO_X9H per PR #6139

# This is the commit message #2:

fix typo

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clarified BLTouch calculation & changed comment delimitters/flags

I found it hard to pickout the various sections in this area so I
changed most comments from // style to /** ... */

Made the BLTouch calculation simpler and clarified the units of measure
for the result.

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add changes to example configurations

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add TinyBoy2 to this PR & add BLTouch Delay

The offset for Z_DUAL_ENDSTOP (z_endstop_adj) is already in Marlin.
This PR just makes it a configuration item.

z_endstop_adj is initialized in two places so both had to be modified.

The OLED is driven by an SSD1306, connected to the board via
I2C, the rotary encoder is connected to 3 GPIO pins.

Signed-off-by: Stefan Brüns <stefan.bruens@rwth-aachen.de>