Make websocket headers case insensitive, better cookie header handling

[evanbsmith]

• Per Websocket/HTTP spec, updated to allow case-insensitivity in websocket/HTTP headers
• Updated "set-cookie" header to allow for multiple cookie values, saving first one as sid
• Add debug code to print client websocket request headers

[lhovo]

Using this code for the case-insensitivity, it's working well