added video scale factor to paprika start routine

video is resized accordingly using CSS transform property
also factored out default video width and height for easier maintenance
added scale factor to phaser demos

video is now displayed a 50% of its size
also added description for phaser_demo_3 from gh-pages
updated asteroids game

added controller cards for mirror and top view modes
game logic slightly changed, added audio
added icons for card modes

used in phaser demos when two controls modes are available to
differentiate between mirror and top view camera modes