Blender Git Loki

Use BLI_delaunay_2d_cdt prefix for public API

BLI_constrained_ is too generic & doesn't match the filename.

Rename struct members

Opinionated changes for struct names.

- Use plural for faces/edges/verts.

- Was using len / num in a confusing way.

Now lookup tables use a `_table` suffix, so we can have.

- faces_len (length of the array).
- faces_len_table (length of each face).

Pass __func__ to allocations

Makes memory allocations easier to track down.

Cleanup: add braces

Cleanup: compiler warnings

Cleanup: comments, use sentences, some minor spelling corrections

Cleanup: use doxy docs

Initial D5423 (by @howardt)