Added User authentication

MediaBrowser.Api/HttpHandlers/UserAuthenticationHandler.cs

@@ -0,0 +1,28 @@
+using System;
+using System.Linq;
+using System.Threading.Tasks;
+using MediaBrowser.Common.Net.Handlers;
+using MediaBrowser.Controller;
+using MediaBrowser.Model.DTO;
+using MediaBrowser.Model.Entities;
+
+namespace MediaBrowser.Api.HttpHandlers
+{
+    class UserAuthenticationHandler : BaseSerializationHandler<AuthenticationResult>
+    {
+        protected override async Task<AuthenticationResult> GetObjectToSerialize()
+        {
+            Guid userId = Guid.Parse(QueryString["userid"]);
+            User user = Kernel.Instance.Users.First(u => u.Id == userId);
+
+            string password = await GetFormValue("password").ConfigureAwait(false);
+
+            AuthenticationResult result = new AuthenticationResult()
+            {
+                Success = true
+            };
+
+            return result;
+        }
+    }
+}