added mapping to emby and plex nodes

added ability to override server/token/mapping for emby/plex nodes

Emby/Tests/EmbyTests.cs

@@ -33,6 +33,19 @@ public class EmbyTests
         var node = new EmbyUpdater();
         Assert.AreEqual(2, node.Execute(args));
     }
+
+    [TestMethod]
+    public void Emby_Mapped()
+    {
+        var args = new NodeParameters(@"/mnt/movies/Citizen Kane (1941)/Citizen Kane (1941).mp4", new TestLogger(), false, string.Empty);
+        args.GetPluginSettingsJson = (string input) =>
+        {
+            return File.ReadAllText("../../../settings.json");
+        };
+
+        var node = new EmbyUpdater();
+        Assert.AreEqual(1, node.Execute(args));
+    }
 }
 
 #endif