Initial robotpy-cscore support

This release of RobotPy includes initial support for running robotpy-cscore on the RoboRIO. It's lightly tested, but seems to work for the two examples I have... you will need to install robotpy-cscore the same way that you would install robotpy-ctre. See http://robotpy.readthedocs.io/en/latest/vision/index.html for details.

Please report bugs as you find them!