UI and opt-in for setting permissions

src/NzbDrone.Core/Configuration/IConfigService.cs

@@ -42,6 +42,7 @@ namespace NzbDrone.Core.Configuration
         Boolean EnableFailedDownloadHandling { get; set; }
         Boolean CreateEmptySeriesFolders { get; set; }
         void SaveValues(Dictionary<string, object> configValues);
+        Boolean SetPermissionsLinux { get; set; }
         String FileChmod { get; set; }
         String FolderChmod { get; set; }
     }