mod_h[ttp]2 v1.7.8

• unannounced and multiple interim responses (status code < 200)
  are parsed and forwarded to client until a final response arrives.
• allocators from slave connections are released earlier, resulting
  in less overall memory use on busy, long lived connections.
• mod_proxy_http2: improved robustness when main connection is closed early
  by resetting all ongoing streams against the backend.