BSD 4-clause is GPL-incomatible

[voxpelli]

Spurred by https://github.com/prusa3d/libbgcode/issues/24 I wanted to open an issue here and notify you that the change from AGPL to BSD 4-clause unfortunately introduced an incompatibility with GPL-code, as outlined by the FSF here: https://www.gnu.org/licenses/license-list.html#OriginalBSD

FSF themselves recommends using eg. Apache 2.0 instead or the MIT / X11 / Expat license.

On top of that there's nowadays the Blue Oak License that aims to bring the best of the best from all of them (the result of a work of evaluating most permissive licenses and ranking them)

Related change: https://github.com/scottmudge/OctoPrint-MeatPack/commit/dd8776e4cf0df540798dd62f6bb7aa481bdd8181