Reworked the driving code completely.

Instead of being one big file (BestRobotDrive.java) I split it up to make it
easier to understand, more flexible and follow better OOP practices. This makes
it easy to add extra motors or make other changes. Lastly, I changed the
commands and DriveSubsytem to make use of the new code.
Remove BestRobotDrive.java since the new system no longer uses it.

It was in a state of half conversion to an 8 motor system and was a horrible
mess in the first place so I decided it was no longer necessary. If I need to
reference the algorithms, I can just look at another branch. I also removed one
last accidental reference to BestRobotDrive that remained in the new system.