Define SoupMessage signal stuff (READ_HEADERS, READ_CHUNK, READ_BODY,

Define SoupMessage signal stuff (READ_HEADERS, READ_CHUNK, READ_BODY,

	* libsoup/soup-message-private.h: Define SoupMessage signal stuff
	(READ_HEADERS, READ_CHUNK, READ_BODY, READ_ERROR, WROTE_HEADERS,
	WROTE_CHUNK, WROTE_BODY, WRITE_ERROR).

	* libsoup/soup-message.c (class_init): set up signals
	(requeue_read_finished): Update for changes.

	* libsoup/soup-message-io.c (soup_message_read): Split out
	parse_headers_cb from read_headers_cb. Also add a SoupDataBuffer *
	arg to say where to store the message body. Set up
	read_headers_cb, read_chunk_cb, read_body_cb, and error_cb as
	signal handlers.
	(do_read): Call r->parse_headers_cb, then emit READ_HEADERS
	(read_body_chunk): emit READ_CHUNK.
	(issue_final_callback): Set r->body. emit READ_BODY.
	(failed_read): emit READ_ERROR.
	(soup_message_read_set_callbacks): Disconnect old signal handlers,
	connect new ones.
	(soup_message_read_cancel): Disconnect signal handlers.
	(soup_message_write, soup_message_write_simple): Set up
	wrote_body_cb and error_cb as signal handlers.
	(do_write): emit WROTE_HEADERS and WROTE_CHUNK, even though
	nothing currently ever listens for them. emit WROTE_BODY when
	done.
	(failed_write): emit WRITE_ERROR

	* libsoup/soup-queue.c (soup_queue_parse_headers_cb,
	soup_queue_read_headers_cb): Split this into two unequal chunks.
	(read_header_cb only runs the pre-body handlers).
	(soup_queue_read_chunk_cb, soup_queue_read_done_cb): Update
	prototypes.
	(soup_queue_write_done_cb): Update call to soup_message_read

	* libsoup/soup-server.c (parse_headers_cb): Renamed from
	read_headers_cb
	(read_done_cb): Update prototype
	(start_request): Update soup_message_read call.