PTB - Enable support for container pages

gistfile1.cs

        protected internal virtual IPageType CreateNewPageType(PageTypeDefinition definition)
        {
            IPageType pageType = PageTypeRepository.CreateNew();

            PageTypeAttribute attribute = definition.Attribute;

            string name = attribute.Name;
            if (name == null)
            {
                name = definition.Type.Name;
            }
            pageType.Name = name;
            
            if (definition.Attribute.Guid.HasValue)
                pageType.GUID = definition.Attribute.Guid.Value;

            string filename = attribute.Filename;
            
            // check for null rather than IsNullOrEmpty, that way a developer can set filename="" and use the pagetype as a container page.
            // OLD CODE -- if (string.IsNullOrEmpty(filename))
            if (filename == null)
            {
                filename = DefaultFilename;
            }
            pageType.FileName = filename;
            
            PageTypeRepository.Save(pageType);

            NewlyCreatedPageTypes.Add(pageType);
            return pageType;
        }