Added BannerDownloadJob, it will run every 30 days.

New series will have their banner downloaded on import.

NzbDrone.Core/Repository/Series.cs

@@ -37,6 +37,10 @@ namespace NzbDrone.Core.Repository
 
         public DateTime? LastDiskSync { get; set; }
 
+        public int Runtime { get; set; }
+
+        public string BannerUrl { get; set; }
+
         /// <summary>
         /// Gets or sets a value indicating whether this <see cref="Series"/> is hidden.
         /// </summary>