Takes a collection of records,
sorts it according to $sort_routine,
and then prints it to standard output using Prophet::Record-format_summary> as the format.
Given a property name and an arrayref to a list of records,
returns a list of the records sorted by their created property,
in ascending order.
If $sort_undef_last is true, records which don't have a property defined are sorted *after* all other records; otherwise, they are sorted before.
Given a property name and an arrayref to a list of records, returns a reference to a list of hashes of the form:
{ label => $label,
records => \@records }