Core - Ensure application data folder exists

UI - Properly catch exceptions during exception display
UI - Display fatal exceptions during Core creation, even before Core initialisation

src/Artemis.Core/Services/RgbService.cs

@@ -1,8 +1,6 @@
 using System;
 using System.Collections.Generic;
-using System.Linq;
 using Artemis.Core.Events;
-using Artemis.Core.Plugins.Abstract;
 using Artemis.Core.Plugins.Models;
 using Artemis.Core.RGB.NET;
 using Artemis.Core.Services.Interfaces;