These extra points are unnecessary and can confuse the partitioner,
because they sometimes prevent it from detecting winding numbers
properly. This is a bug in the partitioner and should be fixed, but we
shouldn't be generating these points to begin with.
Partially addresses #57.
I'm not too happy with this, as I discovered a segfault in FreeType that doesn't give me confidence
in this as a solution for the long term. Additionally, this exposes the problems in the partitioner
with lack of winding fill rule, proper handling of self-intersections, and splitting of paths at
their extrema. (I believe these problems should be fairly straightforward to handle, but we just
don't handle them yet.)
Patrick Walton