Sync with v2.0.10 from github:

 * Extensive testing in production done by Alessandro Bianchi (@alexskynet)
   on the v2.0.x versions for stability. Many thanks!
 * refactored stream response handling to reflect the different phases
   (response/data/trailers) more clearly and help resolving cpu busy loops.
 * Adding more negative tests for handling of errored responses to cover
   edge cases.
 * mod_http2: fixed handling of response where neiter an EOS nor an ERROR was
   received as a cause to reset the stream.
 * mod_proxy_http2: generating error buckets for fault response bodies, to
   signal failure to fron when response header were already sent.

v2.0.9
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 * Fixed a bug where errors during reponse body handling did not lead to
   a proper RST_STREAM. Instead processing went into an infinite loop.
   Extended test cases to catch this condition.

v2.0.8
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 * Delaying input setup of a stream just before processing starts. This allows
   any EOS indicator arriving from the client before that to take effect.
   Without knowing that a stream has no input, internal processing has to
   simulate chunked encoding. This is not wrong, but somewhat more expensive
   and mod_security has been reported to be allergic to seeing 'chunked'
   on some requests. See <https://bz.apache.org/bugzilla/show_bug.cgi?id=66282>.
 * mod_proxy_http2: fixed #235 by no longer forwarding 'Host:' header when
   request ':authority' is known. Improved test case that did not catch that
   the previous 'fix' was incorrect.



git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1904522 13f79535-47bb-0310-9956-ffa450edef68
