add allQuadratic=False option to allow building glyf v1 with cubics

[anthrotype]

that is, a mix of cubics or quadratic depending on which is more economical. In practice, all cubics are kept as such and only converted to quad if they can be approximated by a single quad (1 off-curve point vs original 2)

[behdad]

Should it also set the glyf version to 1?

[anthrotype]

github acting weird 😞 https://www.githubstatus.com/

We are investigating an issue which is causing a delay in the time it takes new commits to show up on a pull request.

[anthrotype]

Should it also set the glyf version to 1?

probably yeah