Added safety pragmas on states. Generalized liveness check as a safety check

src/main/java/avatartranslator/AvatarExpressionSolver.java

...ava/avatartranslator/modelchecker/AvatarModelChecker.java

...in/java/avatartranslator/modelchecker/SafetyProperty.java

...ava/avatartranslator/modelchecker/SpecificationState.java

src/main/java/ui/window/JDialogAvatarModelChecker.java