Merge branch 'nodeasteroids'

added all files

to remove files

added readme

asteroids in node.js

cleaned

added asteroid image

Create README.md

fixed bugs, removed flickering, added score, added game over mechanism

changes by @niklabh to make game playable still some bus though

Fix spacing in asteroids.html.

Refactor game.js.

Refactor Game class and add semi-colons where necessary.

Refactor Bullet class.

Rename variables for window width and height to w_width and w_height.