* dbusbind.c (all): Replace XCAR by CAR_SAFE and XCDR by CDR_SAFE.

* dbusbind.c (all): Replace XCAR by CAR_SAFE and XCDR by CDR_SAFE.
(xd_signature, xd_append_arg): Handle element type detection for
empty arrays.
(Fdbus_call_method, Fdbus_send_signal): Undo type casting for
SDATA () calls; this must be solved more general.
(Fdbus_register_signal): Use SBYTES instead of strlen.