Accessing packed files

    * To get the host archive from a packed program:

       my $zip = PAR::par_handle($0); # an Archive::Zip object
       my $content = $zip->contents('MANIFEST');

    * Same thing, but with read_file():

       my $content = PAR::read_file('MANIFEST');

    * Loaded PAR files are stored in %PAR::LibCache:

       use PAR '/home/mylibs/*.par';
       while (my ($filename, $zip) = each %PAR::LibCache) {
           print "[$filename - MANIFEST]\n";
           print $zip->contents('MANIFEST');
       }