Dev/jpsnyder/debug/led

- Cleaned up sprite implementation and fixed some bugs.
- Implemented line function in C instead of python.
- added a "tests" folder and the ability to run these tests by calling "setup.py test" in the terminal

For that performance difference, I'd rather stick with Python.  Interesting your comment about floating point numbers - why do you say that?  It should be using whatever type the user passed in, which has to be integers or point() will throw an exception.