http-parser c5c45636b85e7598223adede6ba2d8cb8fe03ebe

Fix for compilation against modern LibreSSL

Larger frame size just destroys multiplexing and prioritization does
not work.

Fix compilation with boringssl

Explicitly set install location when building shared libs

-[0-9] is valid option, but we don't use them so far and don't want to
 mark integer -1 as option.

Now http_parser_parse_url returns nonzero if empty URI is given.

Pool HTTP/1.1 backend connection per address and reuse it only when
the next round robin index refers to this address.  Previously if
there is a pooled connection, there is no round robin selection.