case insensitive http headers

Svetlin wrote on github

According to RFC2616, all header field names in both HTTP requests and HTTP responses are case-insensitive. But libwebsockets uses a case-sensitive compare.

Reproduce:
Run libwebsockets against a server that sends all of its HTTP header field names in lower-case (for example: https://github.com/extend/cowboy). libwebsockets reports an error. The expected behavior is no errors reported and a successful handshake procedure.


This changes the parser reference table in minilex to all lower case.

The code to walk the parser tables then just forces a tolower on the incoming chars.

This (and minilex tables) only applies to header names.

Reported-by: svetlin-mladnov <?@github>
Signed-off-by: Andy Green <andy.green@linaro.org>