http://mozakai.blogspot.jp/2012/03/howto-port-cc-library-to-javascript.html
http://q.hatena.ne.jp/1367064416
http://qiita.com/kjunichi/items/47715431c1228bfdda90
http://qiita.com/sassy_watson/items/3ec69b19a22a457362a9
http://hujimi.seesaa.net/article/264965970.html
サンプル
https://github.com/ukyo/emscripten-fileio