Update the play-icon.png with a circular and text version of a logo with rocket.
Added play-icon-square.png and play-icon-round.png for sake of visualizing other ways to show the icon
Have 'wallpapers' folder in case you wanted to supply users with wallpapers, which I'd be willing to contribute some of my photography towards, open source of course.
Originals folder was just to make sure I didn't lose your original and could be removed.
fixes #66