Merge pull request #9 from breaks/master

Adding keyboard support (only shooting works at the moment)
add WASD support for movement, fix key events to only trigger on canvas element
cleanup some stuff
change background image to use img element instead of drawing direct, gifs work now
change fire limit to 10 bullets every 2 seconds, swap mouse buttons to
match other games
todo: make a swap mouse button, button?
fix package.json, remove unused jquery.js