0.3.5

• Added a settings button and viewer selector UI to pick between Cardboard V1 and Cardboard V2 parameters, which includes distortion coefficients and FOV.
• Added viewerchange event, which fires when viewer parameters change.
• Added modechange event, which fires when the current viewing mode changes (eg. normal to fullscreen to VR).
• Added an aligner UI on the middle of the screen.
• Fixed video playback issue.
• Bugfixes and minor refactoring.