[ZOOM] issue #31: cleaning code

src/main/java/ui/avatardd/ADDArtifact.java

src/main/java/ui/avatardd/ADDBlockArtifact.java

src/main/java/ui/avatardd/ADDBridgeNode.java

src/main/java/ui/avatardd/ADDBusNode.java

src/main/java/ui/avatardd/ADDChannelArtifact.java

src/main/java/ui/avatardd/ADDClusterNode.java

src/main/java/ui/avatardd/ADDCommunicationNode.java

src/main/java/ui/avatardd/ADDConnector.java