es6 modules - unwrap amd modules

[spalger]

amd modules are not compatible with import statements, this transforms:

define(function (require) {
  var _ = require('lodash');
  return function () {
    //...
  };
});

into:

export default function () {
  var _ = require('lodash');
  //...
};

[spalger]

We need to do this last, since the load order of modules using amd is important this depends on all other changes first