Please change the API's CORS restrictions

[benmanone]

I think the current CORS settings are far too restrictive, preventing the API from sharing responses with other domains. Please could the Access-Control-Allow-Origin header be modified to allow those of us who want to build web apps using the API to do so? I don't know very much about API development but I think this is a very simple task. I could try to write a PR doing this later today. Thank you