deleted NumberLiteral.java; commented out analyze() in several class files
removed empty Literal files
removed unimplemented ReturnStatement class; commented out analyze() in some classes
commented out analyze() in PrintStatement.java and Program.java
removed unimplemented ObjectExpression.java and ObjectType.java
commented out analyze() in LoopStatement.java and Number.java
deleted unimplemented IndexVariableExpression.java
deleted unimplemented CallStatement.java