Dc/encoder status

[dcowden]

This branch changes a LOT of things

• DriveEncoderStatus now wraps up encoder status, so that other components can see it
• DriveComponent is now lighter weight-- it doesnt have a periodic() method, so that a bit more of what's going on is in the main loop. I think this is more flexible.
• Remove FourTalonsWithSettings in favor of a simpler FourTalonsGroup object
• Added FourWheelSpeedDrive, which replaces wpilib ArcadeDrive
• Added FourWheelPositionDrive, which uses the new libraries
• Changed builders so that you configure just what you need. This eliminates the possibility of settings that conflict with the selected drive mode

[dcowden]

WIP: do not merge yet.