Sg tweak

Does the following:

1. Fixes camelCase.

2. indexes/vertexes -> indices/vertices.

3. Fixes a couple tests.

4. Fixes module packaging in `setup.py`.

There should be only one failing test now, and it fails in all backends (`gloo`-change related). @almarklein @lcampagn you'll probably have to sort that one out...
@almarklein note that I had to make several changes to `scenegraph` in order for it to even import properly. None of the `scenegraph` examples work on my machine.