Xwt.BitmapImage: ImageFormat Format property introduced
Xwt.Swf:GdiImageBackendHandler.GetFormat implemented
Limaki.View.DragDrop: drag Uri (files) implemented
Limaki.View.XwtBackend: use BitmapImage.Format
Limaki.View.SwfBackend.DragDrop: compare dragdropformats with XwtTransferTypes
Limaki.View.VisualsDragDropAction: check if source is null (nothing is selected)
cleanups; remove obsoletes
Xwt.Gtk: try to avoid infinit loop in OnSizeAllocated (see: https://github.com/limada/limada/issues/22); remark: no success