[Mono.Addins framework implemented]
* Format.cs:
* FormatValidation.cs: Removed parameterized constructor for
  Mono.Addins
Marked as extension point

* GameFile.cs: Removed parameterized constructor of Format

* XmlExportable.cs: Marked as extension point

* Program.cs: Added Mono.Addins initialization

* Worker.cs: Added autosearch of type by using FormatValidation