The Perl5 module "Pod::Usage" which provides the function "pod2usage()"
to print usage messages for a Perl script based on its embedded
pod documentation. Pod::Usage is a subclass of Pod::PlainText.
Please see the POD documentation for this module (embedded in the
file "Usage.pm") for more details. The pod2usage() function is
probably the most generally useful function in this entire distribution
since it is useful to just about any Perl5 script that is invoked
from the command-line.