Pretty Printer

The only known issue (apart from the slight ugliness of the code due to the nontrivial rules for pretty whitespace) is that the main method is pretty printed as `public void main(String[] args) {...` (dropping the `static`).
Would it be Better Scala Style (TM) to do `ast.classes.sortBy{...}.foreach(printClassDecl)`? (Not tested, just guessing.) If yes, please also change other usages.