MINOR: proto_reverse_connect: parse rev@ addresses for bind

MINOR: proto_reverse_connect: parse rev@ addresses for bind

Implement parsing for "rev@" addresses on bind line. On config parsing,
server name is stored on the bind_conf.

Several new callbacks are defined on reverse_connect protocol to
complete parsing. listen callback is used to retrieve the server
instance from the bind_conf server name. If found, the server instance
is stored on the receiver. Checks are implemented to ensure HTTP/2
protocol only is used by the server.