title: babel/6to5 - duplicated code when exporting modules
body: <p>I'm using Babel to transpile ES6 to ES5 and it works great.
  The only problem is that once transpiled each module duplicates these lines:</p>
  
  <pre><code>var _get = function get(object, property, receiver) { var desc = Object.getOwnPropertyDescriptor(object, property); if (desc === undefined) { var parent = Object.getPrototypeOf(object); if (parent === null) { return undefined; } else { return get(parent, property, receiver); } } else if ("value" in desc &amp;&amp; desc.writable) { return desc.value; } else { var getter = desc.get; if (getter === undefined) { return undefined; } return getter.call(receiver); } };
  var _inherits = function (subClass, superClass) { if (typeof superClass !== "function" &amp;&amp; superClass !== null) { throw new TypeError("Super expression must either be null or a function, not " + typeof superClass); } subClass.prototype = Object.create(superClass &amp;&amp; superClass.prototype, { constructor: { value: subClass, enumerable: false, writable: true, configurable: true } }); if (superClass) subClass.__proto__ = superClass; };
  var _classCallCheck = function (instance, Constructor) { if (!(instance instanceof Constructor)) { throw new TypeError("Cannot call a class as a function"); } };
  </code></pre>
  
  <p>As my application is going to have more and more modules defining classes, I cannot imagine waisting so much space just because of these repeated code.</p>
  
  <p>Is there a way to tell Babel to not include them in each module so we can add them only once later ?</p>
  
  <p>I'm using gulp and my config is:</p>
  
  <pre><code>var gulp = require('gulp');
  var concat = require('gulp-concat');
  var babel = require('gulp-babel');
  
  gulp.task('default', function () {  
  
      return gulp.src('src/**/*.es6')
          .pipe(babel({ playground: true, experimental: true, modules: 'amd', moduleIds: true }))
          .pipe(concat('tmp/src.js'))
          .pipe(gulp.dest('dist'));
  });
  </code></pre>
  
  <p>Thanks a lot for your help!</p>