This commit also changes SPDY's flow control size. Previously,
the size for SPDY is the same amount of bytes with HTTP/2.
For example, --frontend-http2-upstream-window-bits=N,
the window size is 2**N - 1. Now SPDY code uses 2**N.
Remove sorting headers from library code. The application must sort
them if necessary. nghttpx and nghttpd do the sorting of the headers
in stable way if names are equal.
nghttp2_session_client_new2 and nghttp2_session_server_new2 take
additional parameters which specifies session options.
nghttp2_set_option is somewhat crumsy because of type checking.
Now we use nghttp2_opt_set, which specifies individual options with
types. We changed the value of nghttp2_opt, so this change will
require re-compile.
Tatsuhiro Tsujikawa