Changed plugins to abstract classes

src/Artemis.Storage/Entities/SettingEntity.cs

@@ -1,4 +1,5 @@
-using System.ComponentModel.DataAnnotations;
+using System;
+using System.ComponentModel.DataAnnotations;
 
 namespace Artemis.Storage.Entities
 {
@@ -7,6 +8,8 @@ namespace Artemis.Storage.Entities
         [Key]
         public string Name { get; set; }
 
+        public Guid PluginGuid { get; set; }
+
         public string Value { get; set; }
     }
 }