Rename bit field for more consistent naming.
Change all constants to constexpr
Implement ControlLoop to replace SampleAndControl.
Move Encoder methods to -inl file.
Add simple templatized Matrix class.
Add simple templatized 1st order SISO filter class.
Move simple motor methods to motor-inl.h.
Use first order filter in rear_motor_controller implementation.
Use ControlLoop shell command.
Add steer motor state logging code.
Update Makefile.