WIP: Add interaction style to provide navigation from a wand

vtkVRWandNavigationStyle is an interaction style that uses a wand input device's orientation and joystick controls to change the camera position. This style assumes that the wand device has at least one joystick control that produce analog events with 2 elements corresponding to forward/backward motion in the first element and left/right motion in the second element. Forward/backward motion is converted to forward/backward motion of the camera (TODO: in the direction that the wand points). Left/right motion produces rotation about the current camera's up vector (TODO: add styles that rotate about the camera's forward and right vectors).