first steps for #55. implemented the drop listener
working on #55: adapted the toString method to include the information in the new tmp_lp_orig field
working on #55: changed the editor to add the dropped landparcel into the right list and store it in the new tmp_lp_orig field. in the prepareForSave method this information is used to get the kicker and set the right fields
fixes #55: dropped landparcel is propperly stored in the system after save :-)
Merge branch 'feature/55-drag-drop-landparcels-into-riss-editor' into dev