Changes for version 2.22 - 2019-03-17
- Minor change to Makefile.PL to add link with libpng12,libz (avoids PERL_DL_NONLAZY error with SciPDL), and also to search SciPDL directory /Applications/PDL/pgplot
- fixes to tests to work on Perl 5.26+
- metadata updates
- PGPLOT - allow subroutines in the PGPLOT graphics library to be called from Perl.