Case sensitivity of HTTP Response headers

[uncletammy]

I have noticed many occasions where frameworks fail to be detected by their HTTP Response headers in Chromesniffer. It appears that while the response header values are converted to lower case before they are compared against the knownHeaders object in background.js, the key names are not converted.

This is resulting in frameworks which issue server responses with X-Powered-By headers instead of x-powered-by headers, not being detected. Would you merge a PR that iterates through the response headers and converts all key names to lower case? Thanks!

[FranklinYu]

Would you merge a PR that iterates through the response headers and converts all key names to lower case?

@uncletammy Which one?