CORS header comparisons should be case-insensitive

[Eilon]

Per the spec:

http://www.w3.org/TR/cors/#terminology

A header is said to be a simple header if the header field name is an ASCII case-insensitive match for Accept, Accept-Language, or Content-Language or if it is an ASCII case-insensitive match for Content-Type and the header field value media type (excluding parameters) is an ASCII case-insensitive match for application/x-www-form-urlencoded, multipart/form-data, or text/plain.

[kichalla]

38728a6

[Eilon]

@kichalla please update the labels on this issue!

[kichalla]

Sure, I added Done label. Thanks.

[Eilon]

And remove the other status labels please thanks 😄