Still debugging skeletal animation.

Also changed Time, JankCatcher, and LoopLog singletons to enums.
The bone quat-to-matrix math seems to be working, but the model is not
transformed when rendered. I think there's a shader problem.
Added AOSP copyright notice in MatrixUtils

I'm unsure whether it's necessary, but I decided to play it safe.
I also added the corresponding NOTICE file to the project.
Added Apache License boilerplate to export.py
Improved export.py
Improved Material.java

Endianness is now taken into account when loading bytes to the vbo array.
The number of bytes per vertex is also considered.
This references issue #2.
Fixed derp in Light.java

Wasn't an error per se, but was inefficient.
This closes #13.