Proof of concept of configurable "Ease-Down" with a slope and start Z

[thingsapart]

Ease down along the desired polygonal path - slight modification of the original code to support an angle and a "start offset Z" above desired Z (rampZ in the code).

Recap of the code/algo:

1. Travel from first (ie. starting) fromPoint to closest point on polygon at rampZ above that that point,
2. ease-down along one or more points of the polygon, decreasing Z at a fixed slope until target Z is reached, a. if a long move with desired slope would overshoot target Z, break it up to just hit target Z,
3. note touchdown point and then follow the rest of the path and repeat segments at target Z until touchdown point is reached again (this ensures that the initial ramp is fully cleared at target Z height where needed).

Caveats:

• There was a mention on Discord of the current EaseDown code supporting a configurable angle that just was not shown in the UI - I did not see that here so either I misunderstood the existing code or modified the wrong piece of code and this change already exists somewhere else.

Example: rampZ = 2, degree = 1.

[stewartoallen]

this is great. I haven't forgotten about this and hope to work through getting this integrated in the next few days.