This does not deprecate any current functionality, but prepares the way for future deprecation.
The drive classes now accept void(double) functions, which makes them more flexible.
The C++ API ended up a bit more verbose, but the Java API is really concise with method references, which is >80% of our userbase. For example:
`DifferentialDrive drive = new DifferentialDrive(m_leftMotor::set, m_rightMotor::set);`
Lambdas can be passed to interoperate with vendor motor controller APIs that don't have e.g., set(double), so CTRE doesn't have to maintain their WPI_ classes anymore.
MotorControllerGroup was replaced with PWMMotorController.addFollower() for PWM motor controllers. Users of CAN motor controllers should use their vendor's follower functionality.
Also deprecate SpeedController in favor of motorcontrol.MotorController and
SpeedControllerGroup in favor of motorcontrol.MotorControllerGroup.
The MotorController interface is derived from the SpeedController interface
so that code such as SpeedController x = new VictorSP(1) continues to
compile (just with a warning).
SpeedControllerGroup and MotorControllerGroup are independent classes;
both implement the MotorController interface.
