UP-4042 Guest was challenged for auth for portlet on its layout

https://issues.jasig.org/browse/UP-4042

Guest URL such as http://localhost:8080/uPortal/p/uportal-links for portlet on guest's layout without specifying the folder param forced authentication.  With this change URL can be http://localhost:8080/uPortal/p/uportal-links or http://localhost:8080/uPortal/f/welcome/p/uportal-links and the portlet will be displayed without authentication.
I don't see any usages of this "normal" equals() method.  Perhaps is really going on here is that null folder differences don't matter in determining whether `ContentTuple` instances are semantically `equals()`?  And so the `equalsPossiblyIgnoringNullFolderDifferences()` implementation should simply *be* the `equals()` implementation, ignoring those null folder differences?