Added default application directory
Made application loadable using only .htaccess

Nobody told me you could just *use* SetEnv in a .htaccess file!
Moved index.php back into root directory
Clarified examples of environment variables
Adhered to naming conventions

File name determined by class name instead of function
Removed unnecessary dependency
Added some measure of web-accessible directory protection
Adjusted for faster out-of-the-box set-up
External schema, $table refactoring, reduced code smell
Implemented relationships

I swear I had them implemented before.