package licenses

[DanGrayson]

We need a reliable way to ensure that each package has either been licensed by its authors or been released to the public domain. Perhaps "installPackage" could have two new optional arguments: "Copyright" and "License". The value for "Copyright" could be something like "none, public domain" or "Copyright 2020 J. Doe". The value for License could be something like "GPL 2 or 3". The information would be displayed in the top documentation node for the package.