boundary_loop is, but boundary_loop_all isn't. Also, it looks like the [comment](https://github.com/libigl/libigl-python-bindings/blob/0fbf1c9a82b6986497cec1e98c717a33eaf23f83/src/boundary_loop.cpp#L19) for boundary_loop looks incorrect. (returns longest vs all boundary loops?)
boundary_loop is, but boundary_loop_all isn't.
Also, it looks like the comment for boundary_loop looks incorrect. (returns longest vs all boundary loops?)