Blender Git Loki

Fix T85948 Exact boolean crash with some nonplanar ngons.

Triangulating ngons could fail with the method that was being
used: projecting along the dominant normal axis and then using CDT.
It could fail if the ngon has self crossings or might be so after
the described projection.
Switched to using projection along the normal itself, and also to
using polyfill which produces some kind of triangulation no matter
what in such circumstances. This will also likely be faster if
there are a lot of ngons in the meshes, since the exact arithmetic
CDT was being used before, and now float arithmetic is used.