Add 'Access-Control-Allow-Origin' header

[Zemke]

Hey,

permission is being denied for me, because the Access-Control-Allow-Origin header is missing. If you set Access-Control-Allow-Origin to '*' everyone will be permitted to access the API.

More on this: http://jvaneyck.wordpress.com/2014/01/07/cross-domain-requests-in-javascript/

Nice work on this :+1:, I'd like to use it, but this way I can't.