Added getIcon in IPreviewable, implemented them in the implementing Classes and The Source Classes, because they need tp be viewed in the ElementSelectionController.Therfore I added Ressources to the Project, in the Ressource Folder and the Ressource. resx lists this new changes. On top of that I changed Graph to abstract, according to the draft.
Merge branch 'master'
Changed ExportVisitor and Project to be public