1. A method for modifying a configuration file, the method comprising operating a computing device to perform steps of: receiving a first configuration file for an application; receiving one or more changes to the first configuration file to generate a modified configuration file; incorporating into the modified configuration file an identifier that identifies the first configuration file; receiving a second configuration file for the application; retrieving the first configuration file based on the identifier contained in the modified configuration file; determining a first difference between the first configuration file and the modified configuration file; determining a second difference between the first configuration file and the second configuration file; and displaying the first difference and the second difference.