After further investigation there appears to be a really bizarre issue with DNN 5.X.  In prior releases (such as my 4.9.0 production install) there was a package called "DotNetNuke.Authentication", and it had a FriendlyName of Authentication.  The description was "Allow users to login to the portal".  If you deleted this it would remove the login.ascx and several other files and essentially render your site unusable.

It seems the DNN team has made steps to try remove the ability to accidently remove that critical piece of the installation, but I don't see how they were able to hide the Account Login module.  In DNN 5.1.1 (fresh install), there is a package name in the packages SQL table called "DotNetNuke.Authentication", with the same friendly name, but it says "Allows you to manage authentication settings for sites using Windows Authentication".  HMM, so I can delete this right?  It's only if my site uses Windows Authentication and not forms authentication?

It appears that if you do delete that in a DNN 5.1.1 install the Account Login module disappears as well.  Is it just me or is the description for that module very misleading and the description from previous releases "Allow users to login to the portal" was much more accurate?

There are many more inconsistencies in the "Packages" table on my upgraded DNN 5.1.1 site when you compare it to a fresh install "5.1.1" site, such as packages that are marked as "IsSystemPackage" in a fresh install of DNN 5.1.1 but it is not marked as "IsSystemPackage" in an upgraded release from 4.9.0 to 5.1.1.  The same with minifest data for modules that are NULL in a fresh install of DNN 5.1.1, but have data in them in an upgraded site from 4.9.0 to 5.1.1.

So my question is, how do I resolve all of these inconsistencies in the DNN 5.X database after I upgrade from a previous release such as DNN 4.X???

What is the deal with the "Account Login" module, Also known as the "Authentication" module now in 5.1.1 which says it only supports "Windows Authentication"???