NODEJS Drawing Game

* Original work: http://tutorialzine.com/2012/08/nodejs-drawing-game/
* Demo on Heroku: http://node-drawing-game.herokuapp.com/

TBD:
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Choose if local o network.

Ideas:
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Add a button to change brush size
Add a button to erase the draws
Add a button to save the screen
Add a button to add different colors

Some example games about drawing:
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http://www.agame.com/game/paint-wars.html
http://www.agame.com/game/scribble-2.html
http://www.freewebarcade.com/game/trap-draw/

http://www.freewebarcade.com/game/the-sketcher/