CORS on OPTIONS method

[tooxie]

Fixed the lack of CORS headers on OPTIONS request

[manutenfruits]

I am still getting familiar with git, so sorry if this is not the most proper way of doing this.

There is also a header requested from chrome when trying to use the repository: X-Requested-With. Seems like apart from 'Access-Control-Allow-Headers:Content-Type' needs 'Access-Control-Allow-Headers:Content-Type, X-Requested-With' too.

I have added that too (sorry I forgot to mention that on the original issue) and now it works perfectly. I knew it just because Chrome suggested it, but here's some info about it: http://saltybeagle.com/2009/09/cross-origin-resource-sharing-demo/

[tooxie]

Added also Accept and Origin to the headers list, just in case.

[tooxie]

I would also like @slang800's opinion on this PR, because he introduced this feature in the first place.

[tooxie]

Thanks @manutenfruits for reporting this issue and @slang800 for the review! 👍