Just a quick observation before backport of mod_h2 is proposed... Moving the macro APACHE_CHECK_NGHTTP2 out of acinclude.m4 into modules/http2/config.m4 lets me build (after a ./buildconf) after simply checking out modules/http2/ from trunk.
In terms of ease-of-integration, do we see other modules we expect to utilize libnghttp2, e.g. mod_proxy_http? If so, this probably isn't the right solution, but it makes an interesting and quick stop-gap.
