#3 visualization of leuchte-objects without his mast-object
#2 tests for new Veranlassung and Arbeitsauftrag classes
#2 unused properties remove
fixed #12 #13
fix #14 - create new instances of Veranlassung and Arbeitsauftrag
#15 multiselection - map to tree
#15 multiselection - tree to map
#16 workbench - copy and paste
#17 drag and drop