Fix GCC build with -Werror

timegm.h:30:8: error: C++ style comments are not allowed in ISO C90 [-Werror]
Merge branch 'typo' of https://github.com/alagoutte/nghttp2 into alagoutte-typo
Remove debug output
Return new stream ID from nghttp2_submit_{request, headers, push_promise}

Previously stream ID was assigned just before HEADERS or PUSH_PROMISE
was serialized and nghttp2_submit_{request, headers, push_promise} did
not return stream ID.  The application has to check assigned stream ID
using before_frame_send_callback.  Now it is apparent that priority is
meant to DATA transfer only.  Also application can reorder the
requests if it wants. Therefore we can assign stream ID in
nghttp2_submit_* functions and return stream ID from them.  With this
change, now application does not have to check stream ID using
before_frame_send_callback and its code will be simplified.
Remove adjust_priority_callback

Since we have stream ID immediately available from nghttp2_submit_*,
we don't need adjust_priority_callback.
doc: Update tutorial-client.rst
nghttp: Remove streams from HttpClient
Update doc
python: Fix function include path
Interleave stream DATA more naturally

We simulate resource sharing by decreasing weight.  The thing is if
weight is wrapped, that item continues to send DATA until its weight
gets lowered under the other items.  This commits fix this issue.
Remove nghttp2_ prefix from static function
Remove nghttp2_ prefix from static function, part 2
Code cleanup
doc: Add h2load man page
Add h2load.1 dev version for now to `make` happy
nghttpx: Log :authority for CONNECT request in accesslog
Code cleanup
tests: Fix failmalloc tests
tests: Add failmalloc HPACK test
Update doc