Remove or Refactor Singleton class

[Sqeaky]

The only classes using the singleton's functionality are the Entresol, CatchApp and managers that really don't use its functionality.

The Manager pattern is a suitable replace for the singleton class in all the managers, but CatchApp and the Entresol will require some finessing.

Either refactor or remove the singleton class and insure that that CatchApp and the Entresol are still guaranteed to be singular and that they are destroyed appropriately.