Added Fluent.cs to allow string default extention method eg. "Series.Title.WithDefault(series.SeriesId)"

NzbDrone.Core/Fluent.cs

@@ -0,0 +1,22 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+
+namespace NzbDrone.Core
+{
+    public static class Fluent
+    {
+        public static string WithDefault(this string actual, object defaultValue)
+        {
+            if (defaultValue == null)
+                throw new ArgumentNullException("defaultValue");
+            if (String.IsNullOrWhiteSpace(actual))
+            {
+                return defaultValue.ToString();
+            }
+
+            return actual;
+        }
+    }
+}