bugfix: use zml_util:call_special to call process_tree on every special tag - now does not crash if *special tag is not found, and treats it as a regular tag instead.
bugfix: use zml_util:call_special to call process_tree on every special
tag - now does not crash if *special tag is not found, and treats it as
a regular tag instead.

josephwecker/zml,josephwecker/zml