Introduce Q::Literal and Q::Statement
Introduce Q::Literal and Q::Statement

Now we have the following hierarchies:

Q::Literal
    Q::Literal::None
    Q::Literal::Int
    Q::Literal::Str
    Q::Literal::Array

Q::Statement
    Q::Statement::My
    Q::Statement::Constant
    Q::Statement::Expr
    Q::Statement::If
    Q::Statement::Block
        Q::CompUnit
    Q::Quasi
    Q::Statement::For
    Q::Statement::While
    Q::Statement::Return
    Q::Statement::Sub
    Q::Statement::Macro
    Q::Statement::BEGIN

I nearly added a Q::Op to unite Q::Prefix, Q::Infix and Q::Postfix, too.
But I don't have a good use case for that yet, so in the end I didn't.

masak/007,masak/007,masak/007