Mostly backend models stuff

Changed some models, did some work on database, created a class diagram.

KTUSAPS.Data/Model/Issue.cs

@@ -1,6 +1,7 @@
 using System;
 using System.Collections.Generic;
 using System.ComponentModel.DataAnnotations;
+using System.ComponentModel.DataAnnotations.Schema;
 using System.Linq;
 using System.Text;
 using System.Threading.Tasks;
@@ -9,8 +10,10 @@ namespace KTUSAPS.Data.Model
 {
     public class Issue
     {
+        [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
         public int Id { get; set; }
-
+        [MaxLength(64)]
+        public string UserID { get; set; }
         public string Email { get; set; }
         public bool Anonimous { get; set; }
         public bool Publishable { get; set; }
@@ -20,5 +23,6 @@ namespace KTUSAPS.Data.Model
         public string Description { get; set; }
 
         public PublishedProblem Problem { get; set; }
+        public PublishedFeedback Feedback { get; set; }
     }
 }