huge commit for advanced stats feature.

broke data out into its own library.
may be breaking changes with existing plugins

Data/Models/Client/Stats/EFRating.cs

@@ -0,0 +1,31 @@
+using System;
+using System.ComponentModel.DataAnnotations;
+using System.ComponentModel.DataAnnotations.Schema;
+using Data.Models.Server;
+
+namespace Data.Models.Client.Stats
+{
+    public class EFRating : SharedEntity
+    {
+        [Key]
+        public int RatingId { get; set; }
+        public int RatingHistoryId { get; set; }
+        [ForeignKey("RatingHistoryId")]
+        public virtual EFClientRatingHistory RatingHistory { get; set; }
+        // if null, indicates that the rating is an average rating
+        public long? ServerId { get; set; }
+       // [ForeignKey("ServerId")] can't make this nullable if this annotation is set
+        public virtual EFServer Server { get; set; }
+        [Required]
+        public double Performance { get; set; }
+        [Required]
+        public int Ranking { get; set; }
+        [Required]
+        // indicates if the rating is the latest
+        public bool Newest { get; set; }
+        [Required]
+        public int ActivityAmount { get; set; }
+        [Required]
+        public DateTime When { get; set; } = DateTime.UtcNow;
+    }
+}