Refactor Game Player configuration file writing into autonomous class.
With the inclusion of more emulator engines, such as VICE, and Atari800, some of which use multiple configuration files (and templates), it makes sense to refactor the configuration file writing code from its original place in the EmulatorModel base class, to a new class called ConfigurationWriter.
It can simply be instantiated from a template file, a target file, and a system configuration string, use .Add() to add the template markers and their replacements, and then a call to .Write() will write the resulting configuration file from the template.