Removes the TTL triangulator in favor of the delaunator triangulator.
This removes the only AGPL code in the KiCad codebase and therefore
allows the full project to be licensed under the GPLv3.
* Split up the thirdparty code into the thirdparty folder (#3637)
* Create a new kimath static library containing all the math functions
This is part of cleaning the build system for #1906.
The decision to include the TTL library make KiCad a derivative work
under the terms of the AGPL version 3 or later license.
Add both the GPL3 and AGPL3 license text files and add a readme file
about the KiCad licensing. Contributing to KiCad still falls under
the GPL3+ license.
Fixes lp:1797095
https://bugs.launchpad.net/kicad/+bug/1797095
Seth Hillbrand
Ian McInerney
Jon Evans
Seth Hillbrand
Carsten Schoenert
Wayne Stambaugh