Commit 704e57db4e changed the order
of the parameters to `pyassimp.load`. The new order groups
`filename` and `file_type` which is preferable, but the samples and
other calls to `load` still point to the old order. This fixes that
with named arguments where necessary.
pyassimp returned a list instead of a numpy array when the normals were
empty. This also applies to texture coordinates and other stuff which is
explicitly converted in _finalize_mesh.