sbus: add utility function to simplify message and reply handling This patch adds the ability to hook DBusMessage to a talloc context to remove the need of calling dbus_message_unref(). It also provides an automatical way to detect error in a reply so the caller does not need to parse it manually and the whole code around DBusError can be avoided. Reviewed-by: Lukáš Slebodník <lslebodn@redhat.com> Reviewed-by: Jakub Hrozek <jhrozek@redhat.com>