NWGNUmod_http2

Merged /httpd/httpd/trunk:r1786715,1787051,1787141,1787604,1788672,1788981,1789221,1789224,1789276,1789279,1789395,1789520,1789535,1789692

*) mod_http2: rework of stream resource cleanup to avoid a crash in a close

of a lingering connection. Prohibit special file bucket beaming for

shared buckets. Files sent in stream output now use the stream pool

as read buffer, reducing memory footprint of connections.

[Yann Ylavic, Stefan Eissing]

mod_http2/mod_proxy_http2 improvments as in CHANGES

mod_http2: netware build add new symbol used from nghttp2

mod_proxy_http2: resolving last 2 reported dup symbol clashes

mod_http2: rewrite of how responses and trailers are transferred between

master and slave connection. Reduction of internal states for tasks

and streams, stability. Heuristic id generation for slave connections

to better keep promise of connection ids unique at given point int time.

Fix for mod_cgid interop in high load situtations.

Fix for handling of incoming trailers when no request body is sent.

mod_proxy_http2 no longer shares objects with mod_http2

h2_casecmpstr eliminated, uses backported ap_cstr_casecmp*

mod_http2/mod_proxy_http2 update with latest changes from trunk to 1.5.4.

Update of CMake and Netware makefiles.