OpenScad hex grid generator, customizable

Remixed from https://www.thingiverse.com/thing:1296149 to add changeable parameters. ggrieves' description:

Use this to render perforated surfaces that are structurally strong, but conserve material. The OpenScad file included contains a module that will generate hexagonally perforated 2D sheet of any desired dimension. You can use this in your designs to create artistic or functional surfaces.

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The hexDia parameter is the corner-diameter of the holes by default, if the CornersNotFlats is not true, the holes will fit a hexDia between the flats. The PairWithNE parameter is the upstream default where hexes are placed in pairs, even if it would fall outside of the bounding box. If PairWithNE is false then the paired hex is checked against the bounding box.

The hexgrid_40mm_organizer.stl file was intended for use as vertical tool storage per Adam Savage's "First Order Retrievability" principle per: https://youtu.be/PRpRPsQKLo4?t=1920 -- a big-enough hex grid can organize a b