https-http2-and-wordpress Add HTTP/2 proposal.

I have drafted a starting point for an HTTP/2 proposal. I would like to hash out ideas in this PR so we can get to a point of adding a proposal on Make. I think it'd be better to start things here because Github is good at collaboration. Once we have ideas worked out, we can post on Make for more discussion.

Sep 26 '15 22:09 tollmanz

@johnbillion did some testing and found that $_SERVER['SERVER_PROTOCOL'] is empty when the request is made over HTTP/2.

Sep 27 '15 01:09 tollmanz

Well, $_SERVER['SERVER_PROTOCOL'] on my particular configuration, which is HHVM 3.9.1 on Nginx 1.9.5.

In Nginx's fastcgi_params is the following:

fastcgi_param SERVER_PROTOCOL $server_protocol;

Sep 27 '15 20:09 johnbillion

The null SERVER_PROTOCOL is fixed in nginx trunk and 1.9.6 will include it. I have tested the patch located here: https://github.com/nginx/nginx/commit/20669d1949cc6152ffef1c0834544d2dfa743723.patch against current 1.9.5 and SERVER_PROTOCOL is correctly identified as HTTP/2.0 now. Full phpinfo can be seen here: https://pross.org.uk/test.php

Oct 01 '15 21:10 Pross

@dd32 and I rapped on some ideas about this https://wordpress.slack.com/archives/core-http/p1447823196000022

Nov 18 '15 05:11 tollmanz