Support multipolygons with even-odd fill

[corranwebster]

Looking at the FrameBuffer poly algorithm (see https://github.com/micropython/micropython/blob/4efc5e12b94082af16520e73ecdd53a67ceddfcf/extmod/modframebuf.c#L618-L693) if you are careful about repeating the first points at the end of each sub-polygon (so the lines connect to the start of the sub-polygon, and then to the initial point of the entire multipolygon) then it should draw correctly with even/odd fill. So technically we have support for this right now. But the support is not very user-friendly.

What we would like is something that can do the conversion (list of polygon buffers) -> (single polygon buffer with correct repetitions).

With this, the possibility of support of vector fonts like alright fonts (see #4) may be practical.

[corranwebster]

After a deep-dive it looks like there are corner cases where pixels get drawn in degenerate cases. See: micropython/micropython#18361 for details.