The article Fixing extensions without modifying their code reminded me of another patching technique that I used. My conviction and a hard look on the web had led me to an article Redefine PHP class methods or class giving me a head start to do what I wanted: patching third party code without touching the original to allow easy upgrades.
The Yii Framework is very powerful and it provides a lot of functionality right from the pre-built webapp. One of the nice things that is already established for you as a developer is the Login authentication. While the default configuration simply sets it up to run against an array of hard coded usernames and passwords, the Yii Blog Tutorial provides a how to in connecting that login authentication method to a database so you can run your logins against the registered users. Talk about sweet deal.