* bus/activation.c: (load_directory), (bus_activation_init),
	(bus_activation_activate_service):
	* bus/activation.h:
	* bus/driver.c:
	(bus_driver_handle_activate_service), (bus_driver_handle_message):
	More work on the activation handling.

	* dbus/dbus-errors.h:
	Add some error messages

	* dbus/dbus-message.c: (dbus_message_new_error_reply):
	* dbus/dbus-message.h:
	New function that creates an error message.

	* dbus/dbus-protocol.h:
	Add ACTIVATE_SERVER message.

	* dbus/dbus-server-unix.c: (unix_handle_watch),
	(_dbus_server_new_for_domain_socket):
	Call _dbus_fd_set_close_on_exec.

	* dbus/dbus-sysdeps.c: (make_pipe), (do_exec),
	(_dbus_spawn_async), (_dbus_disable_sigpipe),
	(_dbus_fd_set_close_on_exec):
	* dbus/dbus-sysdeps.h:
	Add _dbus_fd_set_close_on exec function. Also add function that checks
	that all open fds are set to close-on-exec and warns otherwise.

	* dbus/dbus-transport-unix.c:
	(_dbus_transport_new_for_domain_socket):
	Call _dbus_fd_set_close_on_exec.