The `float` keyword should not be on these vars because they conceal
the outer vars, preventing them from obtaining known values before
being passed in `set_bed_level_equation_3pts`. Possibly related to
`Z_RAISE_BETWEEN_PROBING` not functioning.

When probing PCB´s I had the problem that i needed auto-leveling for specific areas (it´s never the same size).
Not much code, but very useful.
Now I use simply G29 L5 R55 F5 B35 P3 to probe a 4x6cm PCB before milling.
I used int for values... might be wrong...
I hope this time I got the right development tree. (tried first with https://github.com/MarlinFirmware/Marlin/pull/1130/commits)

- Auto-detect “switchable” items where possible
- Handle switchable multi-value fields
- Add standard sections to config form
- Add section markers to configurations
- Add value options to configurations
- Remove and re-add fields for loaded configs
- Preserve sections across configs
- Preserve non-added fields
- Style added fields wider & newline by default

Fixed how stepper ISR figure it out when the head (extruder) is going to
Min or Max direction.
Added Homing to Max Endstops.

- Naive implementation, assuming the data sheet pin numbers correspond
to Arduino pin numbers.

- Fetch code now handles github, local, or http: access
- Download button creates a time-stamped inline download
- More complete error messages
- Show warnings when approaching the hourly fetch quota (limit
reloading!)
- Added my test domain (where the _htaccess is deployed)
- `_htaccess` file added to set Access-Control-Allow-Origin “*”
- Marlin logo with css
- Limit selectable areas to avoid annoying selections
- Messages now persist until dismissed
- Default repo for files set to thinkyhead, ‘marlin_configurator’ branch
- Cosmetic changes

Fixed delay-times during Init. REPRAP_DISCOUNT_FULL_GRAPHIC_SMART_CONTROLLER won't get initialized on some Boards because delay was to short.

- Make api.github the default source for configurations
- Remove configurations from the configurator
- Continuation and enhancements

Looks like INVERT_E3_DIR was missing in the configuration.h also as I
did a test compile with 4 extruders and Azteeg X3 Pro defined. So I also
added those lines too. Additional formatting to make the comments line
up better in that section.

Include of language_en.h now behind national language.

All "#define MSG_STR_*" now surrounded by #ifndef and #endif.

+ May decrease the workload for feature developers. They may omit to
update all the language files but "language_en.h". When loading _en
first, all new features give some display, but the new in English.

- May throw some additional warnings about redefinition during compile.

I've insert the define and pointer entries for the Viki 2 and miniViki
from Panucatt in all of the example configs and main config. With these
additions and with pins done in the old single pin.h style...I was able
to get the display working fine save for needing to turn Delta Segments
per Second down. But that's a common graphics lcd issue being looked
into right now.

I need assistance in understanding how the new divided pins files fit
together because my previous attempts at trying to get it to work
appropriately didn't seem successful. This originally came from trying
to find out how to swap the XYZ Min and Max Endstop pins in the Azteeg
X3 Pro. It only comes with one set of connectors and they're Min
Endstops. My previous experience didn't turn out well trying to tell the
firmware to home to the Min Endstops so the best solution I found was to
swap the pins in the firmware. If I'm missing a conflict with a setup
other than delta please let me know, but it makes sense in my setup.

Here were a few changes that I had to make/add lines for the 4th hotend.
A compiling problem in the Temperature.cpp and missing lines in
configuration.h and configuration_adv.h. I added these lines in all of
the example configs too.

- Display fan speed 0-1 as “—“ and 254-255 as “100%”.
- Display 4th extruder instead of the heated bed

- Add a span to the edited text line to provide a highlight
- Scroll and highlight for switch checkboxes also
- Clean up initialization
- More API documentation
- Smarter handling of asynchronous file loading during init

- Animate scrolling to the edited item’s position
- Sanity check file drops and show warnings
- Fix form init / refresh on new configuration drop
- Document the API methods that get/set defines

Browsers may not want to load files outside the folder, but they may be
okay with these relative references within the folder.

- When initializing fields use the configuration to determine the format
- Cache the line for each option for fastest string compare / replace
- Add logging levels for debugging

- Specify HTML5
- Allow drag and drop for loading configurations