Renamed spdylay_req_submit and spdylay_reply_submit as spdylay_submit_request and spdylay_submit_response

Check stream before sending SYN_REPLY and DATA. Don't make stream if incoming SYN_STREAM has FIN and UNIDIRECTIONAL set.

This example program can connect to remote host given in command-line
via SSL and retrieves given path using SPDY protocol.
To build this program, OpenSSL + NPN support is required.

Use stream->pri for priority of SYN_REPLY.