Add Tank Drive subsystem

[ZanyHunter]

Named TankDrive.java 4 Spark motor controllers, 2 on each side drive method with left and right arguments

[ZanyHunter]

Include these methods:

• driveTank with 3 arguments, 2 double arguments, 1 for each joystick, 1 boolean for reversing
• driveArcade with 2 double arguments, 1 for each joystick axis, 1 boolean for reversing
• driveDistanceInches with 2 double arguments, 1 for inches and 1 for maximum speed. This method should be PID.
• driveRotateDegreesRelative with 1 double argument for degrees in rotation. This method should be PID.
• driveRotateDegreesAbsolute with 1 double argument for degrees in rotation. This method should be PID. The only difference between this method and the previous is the previous one sets the current heading as zero, while this one sets the gyro's zero as zero.
• resetEncoders
• calibrateGyro