Consider switching to the new ap_hook_protocol_propose/switch architecture

[jchampio]

httpd 2.4.17 added experimental hooks for automatically handling Upgrade requests (for HTTP/2), which might greatly simplify the module handshake code. Even if it doesn't work out, getting feedback upstream to the mod_http2 devs would be appreciated.

[jchampio]

A huge conversation on the Protocols API is in progress on the httpd dev@ mailing list, starting with this post.

[jchampio]

There's also the benefit that scoreboard entries for module connections would be a little more correct.