start working on connection area enable/disable by the user
further implementation of connection area edit

- disable mouse events on item while editing connection areas
- end edit mode when right click in item again
SVG path instead of div representation of the conn area

DesignerItem.editConnectionAreas and endEditConnectionAreas
remove editConnectionAreas  and endEditConnectionAreas

not needed yet
safety bugfix to return something if the path is hidden
implement getDisabledConnectionAreas and setDisabledConnectionAreas
getConnectionAreas filters out disabled connection areas
fix inheritance connection area definition to prefer north/south if available
dont allow disabling all the connection areas, at least 1 has to be enabled
enable east and west side for incoming/outgoiing connections of ModelDecorator is no port is present on that side
Merge branch 'master' into decorator_connarea
Merge branch 'master' into decorator_connarea
Merge branch 'master' into decorator_connarea
Merge branch 'decorator_connarea'