Deleted MecanumDrive and FixedSpeedMecanum
Updated all references to Mecanum stuff and replaced it with Omni
Added CheesyArcadeDrive 
Transfered TankFieldCentric code to separate command
Rewrote SwitchDrive and changed the way it works
Removed ToggleFieldCentric, replaced with SwitchDrive for different drive modes.
Renamed FieldCentricTankDrive to FieldCentricDrive (this isn't a version of tank drive)
Updated SwitchDrive to reflect previous refactorign of FieldCentricTankDrive to FieldCentricDrive