Update on syntax checking attack trees

src/attacktrees/ANDNode.java

src/attacktrees/AfterNode.java

src/attacktrees/Attack.java

src/attacktrees/AttackNode.java

src/attacktrees/AttackTree.java

src/attacktrees/BeforeNode.java

src/attacktrees/BooleanNode.java

src/attacktrees/ORNode.java

src/attacktrees/SequenceNode.java

src/attacktrees/TimeNode.java

src/avatartranslator/AvatarRelation.java

src/ui/AttackTreePanelTranslator.java

src/ui/GTURTLEModeling.java

src/ui/MainGUI.java

src/ui/atd/ATDAttack.java

src/ui/atd/ATDAttackConnector.java

src/ui/atd/ATDConstraint.java