Added new class GoldbergConfiguration.

Global settings can now be saved and reset.
Language can now be edited (globally).
If Cache is broken, try to forcibly update it from the API.

GoldbergGUI.Core/Models/GoldbergModel.cs

@@ -0,0 +1,13 @@
+using System.Collections.Generic;
+
+namespace GoldbergGUI.Core.Models
+{
+    public class GoldbergConfiguration
+    {
+        public int AppId { get; set; }
+        public List<SteamApp> DlcList { get; set; }
+        public bool Offline { get; set; }
+        public bool DisableNetworking { get; set; }
+        public bool DisableOverlay { get; set; }
+    }
+}