* Renamed the method to fatal().
* Added Error class, but I may be factoring it out and replacing it with strong dependency of PHP built-in Exceptions.
* Cleaned up some other stuff too.
* Updated the Database class to work like a Singleton with a getInstance() method.
* The Database class does not have a private constructor so it can still be instantiated in case someone needs to do so.
* Replaced Logger class with Log class.
* Updated Module to have an instance of the Database object as well as the Model class.
* In my perfect vision for usage, the Module classes should never talk directly to the database, but do so via Models, but I know that's asking a lot, so I'm leaving in some options for folks.
* Updated documentation.
