Change User Model and Add poll model, port !poll but ended up disabling it

Geekbot.net/Database/Models/UserUsedNamesModel.cs

@@ -0,0 +1,15 @@
+using System;
+using System.ComponentModel.DataAnnotations;
+
+namespace Geekbot.net.Database.Models
+{
+    public class UserUsedNamesModel
+    {
+        [Key]
+        public int Id { get; set; }
+
+        public string Name { get; set; }
+        
+        public DateTimeOffset FirstSeen { get; set; }
+    }
+}