Converts a data structure into a sequence of perl statements sufficient for
recreating the original via eval. This module is very similar in concept to
Data::Dumper and Data::Dump, with the major differences being that this module
is designed to output to a stream instead of constructing its output in memory,
and that the traversal over the data structure is effectively breadth first
versus the depth first traversal done by the others.

In fact the data structure is scanned twice, first in breadth first mode to
perform structural analysis, and then in depth first mode to actually produce
the output, but obeying the depth relationships of the first pass.