Remove useless imports
MM modifications : add getRelatedActors() with cache and a Task/Loop can not contain a Task anymore
EEF changes : "Task" feature is read-only on a TaskReference. A
Task/Loop can not contain a Task anymore
Performances : Use the new "getRelatedActors" feature to calculate
actors on a diagram.
Add Graal tests plugin
Minor refactoring : size() > 0 => !isEmpty()
BUGFIX : test was made on java.lang.Package not on org...cinematic...Package