Add a "port" channel
Add a "port" channel

A Spice port channel carry arbitrary data between the Spice client and
the Spice server. It may be used to provide additional services on top
of a Spice connection. For example, a channel can be associated with
the qemu monitor for the client to interact with it, just like any
qemu chardev. Or it may be used with various protocols, such as the
Spice Controller.

A port kind is identified simply by its fqdn, such as org.qemu.monitor,
org.spice.spicy.test or org.ovirt.controller...

The channel is based on Spicevmc which simply tunnels data between
client and server. A few messages have been added:

SPICE_MSG_PORT_INIT: Describes the port state and fqdn name, should be
sent only once when the client connects.

SPICE_MSG_PORT_EVENT: Server port event. SPICE_PORT_EVENT_OPENED and
SPICE_PORT_EVENT_CLOSED are typical values when the chardev is opened
or closed.

SPICE_MSGC_PORT_EVENT: Client port event.

fgouget/spice-protocol,fgouget/spice-protocol,vdiot/spice-protocol,SPICE/spice-protocol,fgouget/spice-protocol,vdiot/spice-protocol,SPICE/spice-protocol,SPICE/spice-protocol,vdiot/spice-protocol