Change a huge number of things in preparation for the 2015 season. Mainly the
changes involve drive code, implementing some of 254's algorithms and improving
documentation.

* Add RadianGyro, which replaces BetterGyro and reports its readings in radians
* Fix TempSensor temperature reporting
* Add default threshold to JoystickAxisButton
* Create DelegateCommand, which wraps another command
* Add documentation to TargetTrackingCommunication
* Add Utils class, which contains a method for getting the robot time
* Remove CrabLeft and CrabRight commands because they were useless
* Make FieldCentricMecanumDriveCommand use ValueProcessors and InertiaGenerator
* Add RotateToCommand, which rotates the robot to face a certain direction
* Add RotateCommand, which rotates the robot relative to its current
  orientation
* Remove redundant timeout from WaitForVisionCommand
* Remove input squaring from ArcadeDriveAlgorithm, this can be done with a
  ValueProcessor
* Split mecanum code into GyroMecanumDriveAlgorithm (for field oriented and
  PID) and MecanumDriveAlgorithm (for normal mecanum)
* Add field oriented polar mecanum code (not tested)
* Allow each motor of a WheelController to be inverted separately
* Create ValueProcessors, which manipulate joystick and motor values
* Add LinearRamper, a ValueProcessor that linearly ramps a value
* Add InertiaGenerator, a ValueProcessor that makes the robot respond faster to
  inputs
* Add Scaler, a ValueProcessor that scale a value by a constant