Xwt.TextEntry.MultiLine: implement in Wpf, missing in Gtk
Remove Playground.DragDrop
Xwt.Wpf.FontBackendHandler: too much conversion of Size
Limaki.XwtBackend: implement DragDrop
Limaki.XwtBackend: implement VisualsTextEditAction
cleanup
Limaki.XwtBackend: implement ImageExporter
Camera / Viewport: refactor Matrix to property
Bug in DrawText | remove scaling of Font in StyleSheets