Webpack optimizations (#140)

* Less repetition in webpack configs. Minify CSS classnames in production.

* Ignore all optional deps of moment.js. Fixes #138

* Added target to webpack config

* Automatically extract all 3rd party modules into a separate 'vendor' chunk

* Inline only assets that are smaller than 10KB

* Added autoprefixer options

* Replaced sinfle babel transforms with the stage-1 preset. Cleaned up webpack configs.

* Do not include hot module replacement in production

src/index.js

@@ -22,7 +22,7 @@ render((
   </AppContainer>
 ), el);
 
-if (module.hot) {
+if (process.env.NODE_ENV !== 'production' && module.hot) {
   module.hot.accept('./root', () => {
     const NextRoot = require('./root').default;
     render((