Create a set of N maximally distinct colors

[sharkdp]

See:

• https://stackoverflow.com/a/4382138
• http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.65.2790
• https://github.com/taketwo/glasbey
• ColorBrewer
• https://medialab.github.io/iwanthue/theory/
• https://mokole.com/palette.html
• https://scicomp.stackexchange.com/questions/20030/selecting-most-scattered-points-from-a-set-of-points
• https://cs.stackexchange.com/questions/22767/choosing-a-subset-to-maximize-the-minimum-distance-between-points
• http://www.usrsb.in/picking-colors.html
• https://en.wikipedia.org/wiki/Farthest-first_traversal
• https://stats.stackexchange.com/questions/118033/best-series-of-colors-to-use-for-differentiating-series-in-publication-quality
• https://graphicdesign.stackexchange.com/questions/3682/where-can-i-find-a-large-palette-set-of-contrasting-colors-for-coloring-many-d

[sharkdp]

# generate 11 distinct colors
cargo distinct 11
cargo distinct 11 --num-iterations 1000000
cargo distinct 11 --max-luminance 0.8

# generate 8 additional colors (start with the given three)
cargo distinct 8 red blue yellow

• [x] write "debug" output to stderr
• [ ] add --max-luminance and similar
• [x] Write long_about text

optimize:

• [ ] do not re-compute all distances (order N^2), but only the once that changed (order N)
• [x] cache the L*a*b* representation in the list of colors to reduce the RGB -> L*a*b* conversion time
• [ ] parallelize the distance-computation?

[sharkdp]

This is almost done, but currently not yet enabled, as it needs to be clean up a bit.