Fix some style errors

First commit inserts semicolons
It's recommended to always use semicolons in JavaScript. Have a look at the point #7 of the accepted answer: http://stackoverflow.com/questions/6950636/justifying-crockford-claims
And this one: http://stackoverflow.com/questions/444080/do-you-recommend-using-semicolons-after-every-statement-in-javascript.

The second commit changes strings that use double quotes to single quotes. This way it is consistent across the file. Most of the JS guys use single quotes now.