net/nmsg: upgrade to version 1.0.0

  The network encapsulation library, nmsg, version 1.0.0 is released.
  This release deprecates Crossroads I/O (libxs) support in favor of
  ZeroMQ (libzmq). Note command-line updates enabling ZeroMQ socket
  connections for nmsgtool, as described in its man page. In addition
  the treatment of unknown rrtypes was amended for nmsgtool JSON
  output. In detail:

    Replace libXS with ZeroMQ and associated calls.

    Developer API functions nmsg_input_open_xs(),
    nmsg_input_open_xs_endpoint(), nmsg_io_add_input_xs_channel(),
    nmsg_output_open_xs(), and nmsg_output_open_xs_endpoint() are
    deprecated and replaced with respectively: nmsg_input_open_zmq(),
    nmsg_input_open_zmq_endpoint(), nmsg_io_add_input_zmq_channel(),
    nmsg_output_open_zmq(), and nmsg_output_open_zmq_endpoint().

    Update nmsgtool command-line options: --readzchan replaces --readzsock,
    --writezsock replaces --writexsock, --readzsock replaces --readxsock.

    Change format of unknown rrtypes in nmsgtool JSON output to "TYPE"
    followed by number.

Expose --without-yajl and --without-libzmq configure flags as port options.

This upgrade changes the libnmsg.so version number, bump PORTREVISION
of the dependent ports.

Sponsored by:	Farsight Security, Inc.