This commit makes sure that WebSocket upgrade works for HTTP/1.1
frontend and backend pair.  Actually, this implementation probably
supports other upgrade as well, other than HTTP/2 Upgrade, which is
handled specially in other place.

Setting TCP_NODELAY may fail. Instead of failing the routine, log it and continue.
It seems, that setting TCP_NODELAY in python on Mac OS X is not necessarily supported.

Use the example presented at
http://en.wikibooks.org/wiki/OpenSSL/Initialization

Official golang spdy package is done.  We made a copy of it until we
drop spdy support.

We may log before filling scheme in Downstream, so we leave
construct_absolute_request_uri as is.

This uninstall-local rule is too strong; it could delete unexpected
files, although they are likely nghttp2 related.

Conflicts:
	src/HttpServer.cc