Mega-patch that gets the message bus daemon initially handling
	out-of-memory. Work still needed. Also lots of random
	moving stuff to DBusError instead of ResultCode.

	* dbus/dbus-list.c (_dbus_list_length_is_one): new function

	* dbus/dbus-connection.c
	(dbus_connection_send_with_reply_and_block): use DBusError

	* dbus/dbus-bus.c: adapt to API changes, make it use DBusError not
	DBusResultCode

	* dbus/dbus-connection.c (dbus_connection_send): drop the result
	code here, as the only failure possible is OOM.

	* bus/connection.c (bus_connection_disconnect):
	rename bus_connection_disconnected as it's a notification only

	* bus/driver.c (bus_driver_handle_acquire_service): don't free
	"name" on get_args failure, should be done by get_args;
	don't disconnect client for bad args, just return an error.
	(bus_driver_handle_service_exists): ditto

	* bus/services.c (bus_services_list): NULL-terminate returned array

	* bus/driver.c (bus_driver_send_service_lost)
	(bus_driver_send_service_acquired): send messages from driver to a
	specific client to the client's unique name, not to the broadcast
	service.

	* dbus/dbus-message.c (decode_header_data): reject messages that
	contain no name field
	(_dbus_message_get_client_serial): rename to
	dbus_message_get_serial and make public
	(_dbus_message_set_serial): rename from set_client_serial
	(_dbus_message_set_reply_serial): make public
	(_dbus_message_get_reply_serial): make public

	* bus/connection.c (bus_connection_foreach): allow stopping
	iteration by returning FALSE from foreach function.

	* dbus/dbus-connection.c (dbus_connection_send_preallocated)
	(dbus_connection_free_preallocated_send)
	(dbus_connection_preallocate_send): new API for sending a message
	without possibility of malloc failure.
	(dbus_connection_send_message): rename to just
	dbus_connection_send (and same for whole function family)

	* dbus/dbus-errors.c (dbus_error_free): make this reinit the error

	* dbus/dbus-sysdeps.c (_dbus_exit): new function

	* bus/activation.c: handle/return errors

	* dbus/dbus-errors.h: add more DBUS_ERROR #define

	* dbus/dbus-sysdeps.c (_dbus_directory_open) (_dbus_file_get_contents)
	(_dbus_directory_get_next_file): use DBusError instead of DBusResultCode
	(_dbus_result_from_errno): move to this file