chore(append/compensate): Create a association

- an association is created, when the source is a compensation boundary
  event via the context menue

related to CAM-874
Merge branch 'master' of github.com:camunda/camunda-modeler
Merge branch 'master' of github.com:camunda/camunda-modeler

Conflicts:
	org.camunda.bpm.modeler/src/org/camunda/bpm/modeler/ui/features/AbstractAppendNodeNodeFeature.java