syntax error message and comments updated

src/main/java/complexityparser/Model.java

src/main/java/complexityparser/tos/TOS.java

src/main/java/complexityparser/types/FOTier.java

.../complexityparser/types/env/OperatorTypingEnvBuilder.java

src/main/java/complexityparser/types/env/TypingEnv.java

...n/java/complexityparser/types/tieredtypes/TieredType.java

...exityparser/typingVisitors/base/BaseStatementVisitor.java

...ava/complexityparser/typingVisitors/base/BaseVisitor.java

src/main/java/view/EditorView.java

src/main/java/view/MessageView.java