Kill jsts

[tcql]

This PR uses the greiner-hormann algorithm that I've been working on implementing. It's considerably faster than JSTS, and removes our dependency on JSTS, aside from turf-buffer.

There are likely some quirks / edge case failures here, but we'll deal with those as they come up. Here's some known differences in the behavior:

• Intersect / Union / Difference no longer will return linestrings or points for cases where polygons touch at only an edge or a point (or several edges or points)
• Returned point orders may be different

[tcql]

oh woops, messed up some of the comments / docblock. I'll fix it up.

[tcql]

Note: I changed the tests and pulled in dev-dependency geojson-equality because point orders in results changed

[anandthakker]

@tchannel @morganherlocker Anything I could do to help this along?

[morganherlocker]

@anandthakker the one remaining JSTS dependency is for polygon buffering.

[anandthakker]

@morganherlocker Oof

[tcql]

@anandthakker I've also noticed a few bugs in the Greiner-Hormann implementation, which I've been chipping away at (tcql/greiner-hormann#15, tcql/greiner-hormann#14)

I also want to clean up, RE: tcql/greiner-hormann#11

[DrColossos]

is there any progress on this? we would love to have this inside turf-intersect since JSTS bloats our build immensely.

[DenisCarriere]

@tcql great work on these commits 👍
I want to merge this, however could you send a PR to the main TurfJS repo instead.

https://github.com/Turfjs/turf/tree/master/packages/turf-intersect

If not, let me know and I can help out with merging it into main Turf repo.

[tcql]

@DenisCarriere the greiner-hormann has some pretty serious bugs that I found after putting this PR together. The package also hasn't been under development recently. I'd still love to circle back sometime and improve it, but for now this dependency murderquest is dead.

[DenisCarriere]

@tcql that's a shame... I'm very PRO removing jsts, however it's not going to be an easy task.