Walk: added Roots closure
Xwt.Application: Initialize with Toolkit as paramter
cleanup
use Xwt.Application(Toolkit)
Limaki.View.Swf.DisplayBackend: DoEvents after Invalidate (speeds up drawing)
Limaki.View.WpfBackend: try to implement ListenClipboard()
Cms.BackendController: set mimetype before and after conversion
Cms.BackendController: use Walk.Roots / Leafs
Cms.BackendController: DescribedThing in Links
VisualsDragDropAction: implement KeyEvent (ctrl-c, ctrl-v)
cleanup
Cms.BackendController: use ThingGraph.Search