Add more properties to the directed links + minor fixes
some fixes for the directed links
Further small fixes for the directed links
change the creation of objects: Instead of showing them in the top left corner the user can set a self-chosen position by clicking on the canvas
small bugfixes for the object creation
Merge branch 'develop' into feature/ResponsivePositioning

* develop:
  small bugfixes for the object creation
  change the creation of objects: Instead of showing them in the top left corner the user can set a self-chosen position by clicking on the canvas
  Further small fixes for the directed links
  some fixes for the directed links
  Add more properties to the directed links + minor fixes