This method, specific to extended processign elements, attempts to
perform all extended processing. By default, it looks at the given
processor's instance variables to determine what to do; e.g.,
processor._4xslt_debug can trigger debug handling.
processor is the active Processor instance.
method is the instantiate method of the original element class.
args are a sequence of arguments (besides self) for the method.
argNames are the names of these arguments, for display purposes
(the names from the method signature, usually). keyword args are
not supported.
name is the display name of the original element.