Defines the extensions to the remote protocol for generic
data streams. Adds a bunch of helper code to the libvirtd
daemon for working with data streams.
* daemon/Makefile.am: Add stream.c/stream.h to build
* daemon/stream.c, qemud/stream.h: Generic helper functions for
creating new streams, associating streams with clients, finding
existing streams for a client and removing/deleting streams.
* src/remote/remote_protocol.x: Add a new 'REMOTE_STREAM' constant
for the 'enum remote_message_type' for encoding stream data
in wire messages. Add a new 'REMOTE_CONTINUE' constant to
'enum remote_message_status' to indicate further data stream
messsages are expected to follow. Document how the
remote_message_header is used to encode data streams
* src/remote/remote_protocol.h: Regenerate
* daemon/dispatch.c: Remove assumption that a error message
sent to client is always type=REMOTE_REPLY. It may now
also be type=REMOTE_STREAM. Add convenient method for
sending outgoing stream data packets. Log and ignore
non-filtered incoming stream packets. Add a method for
serializing a stream error message
* daemon/dispatch.h: Add API for serializing stream errors
and sending stream data packets
* daemon/qemud.h: Add struct qemud_client_stream for tracking
active data streams for clients. Tweak filter function
operation so that it accepts a client object too.
* daemon/qemud.c: Refactor code for free'ing message objects
which have been fully transmitted into separate method.
Release all active streams when client shuts down. Change
filter function to be responsible for queueing the message
