File Release Notes and Changelog

This version has a new file system layout and some minor fixes in particular for the delete_snapshot method. If you are upgrading from an earlier version you want to delete the old files prior to untarring the new set of scripts and running the upgrade_pgstatspack.sh. As always let me know if there are any improvements you would like me to make. --Keith Pierno

Updated README file with new information. Fixed the pgstatspack_delete_old_stats.sql to fix a typo. Reorganized the files so they are better laid out and have a sustainable file structure for future upgrades.