Merge pull request #518 from mozilla/mobile-image-picker

doc/image_orientations.gif

src/assets/hud/spawn_photo-hover.png

src/assets/hud/spawn_photo.png

src/assets/stylesheets/2d-hud.scss

src/components/offset-relative-to.js

src/components/super-spawner.js

src/components/virtual-gamepad-controls.css

src/hub.js

src/react-components/2d-hud.js

src/react-components/ui-root.js

src/utils/media-utils.js