ast: pathToNode helper
ast = lively.ast.acorn.parse('foo(3) + bar()')
lively.ast.acorn.pathToNode(ast, 1, {})
// returns: {
//   node: {/*...*/},
//   path: ["body",0,"expression","left","arguments",0],
//   pathString: ".body[0].expression.left.arguments[0]"
// }
debugging: fix for rewriting new expressions
debugging: fix for rewriting forin expressions
debugging: towards loading from rewritten code