There is no application level failure in h1 upstream.  For h2, SPDY
upstreams, don't call DIE(), instead return -1 to delete handler.

.. so that we can avoid the problem that request_start_time_ is 0

small text fixes

This change adds SPDY upstream tests.

Also HTTP/1 frontend testing method was added.

With array, we can control the order of header field directly.