feat(transpiler): Transform for..of to Dart as for..in

Added transformation of for..of into Dart for..in.  
Added error for JS for..in since the semantics don't match.  
Added error for for..of utilizing destructuring declarations.

Closes #53 
One thing I'm trying to figure out still is how much work would be needed to get the destructuring transformer working. 


> On Nov 27, 2014, at 12:00 PM, Victor Berchet <notifications@github.com> wrote:
> 
> In tools/transpiler/src/outputgeneration/DartParseTreeWriter.js:
> 
> > @@ -465,6 +469,45 @@ export class DartParseTreeWriter extends JavaScriptParseTreeWriter {
> >      this.writeList_(tree.parameterNameAndValues, COMMA, false);
> >    }
> >  
> > +  // FOR LOOPS
> > +  // Translate for..of to for..in and throw error on for..in (JS)
> > +  /**
> > +   * Transforms for..of into for..in.
> > +   * Unsupported:
> > +   *  - Destructuring iterators for map key, value
> Great, thanks!
> 
> —
> Reply to this email directly or view it on GitHub.
>