Build drive command class supporting speed ramping and drive-by-distance

[dawilson9]

To aid autonomous operation, we need a class which sits above the drive subsystem and which has high level methods for driving a given distance and turning a given angle. This must use the IMU or other sensors to provide accurate distance and angle measurement and must support smooth acceleration and deceleration (no sharp discontinuities in motor speed allowed!).

Develop a class interface proposal first then code it. The idea is that this must be general purpose (not tied to a given year's robot design) so that we can reuse it as the core of an autonomous kit-of-software-parts in future seasons. Ideally, we'll tie this in with Ryans CSV path definitions and expand it to support waypoint navigation and advanced control later.

Let's do this one using maths and physics rather than trial and error :-)

[hoo761]

I will create a new branch and start working on this.