Upgrade to Evergreen 3.1

Documentation for upgrade from Evergreen 2.12 to 3.1. Since the upgrade is complete, most of the content from this knowledge book has moved to permanent knowledge books, such as Troubleshooting Evergreen 3.1, Administration Manual for Libraries, and Circulation in Evergreen 3.1. You can also browse the knowledge tags on the home page for the topics you are looking for.