v2017.1.0

Additional support for command-based robots (#116)

* Add a CommandRobot base

Takes care of the boilerplate for running the scheduler.
Does not implement any of the logic for selecting or creating autonomous modes.

* Add SubsystemCommand to extras

It behaves as a regular command, but automatically calls `.Requires` on the provided subsystem and stores a reference to it as `m_subsystem`

* Fix comments to provide more accurate description