Bug resolution on guard management

src/main/java/avatartranslator/AvatarGuard.java

src/main/java/avatartranslator/AvatarSyntaxChecker.java

src/main/java/ui/AvatarDesignPanelTranslator.java

src/main/java/ui/TGComboBoxWithHelp.java

src/main/java/ui/TGHelpButton.java

src/main/java/ui/window/JDialogProverifVerification.java

src/main/resources/help/securityverification.html

.../src/test/java/avatartranslator/AvatarExpressionTest.java

ttool/src/test/java/avatartranslator/AvatarGuardTests.java