* Polyfill for IE9 support

* Turn off performance option in webpack

* Turn on helpers and test importing something with async/await works

* Compiling babel runtime breaks itself

* Add helpers option to babel plugin with defaults

* Make helpers off by default and on in our configuration

* Hit eject and e2e

* meh

* copy'n'paste

* change again

* Turn off helpers by default in /prod, /dev, /test

* oops

* Spread undefined

* Use object assign not object spread

* Put preset in template since it's needed

* Fix e2e tests

Uglify is no longer maintained and has bugs not present in Terser (its successor)

- [x] Utilize webpack 4 development and production modes
- [x] Upgrade webpack dev server
- [x] Webpack 4 compatible release of thread-loader
- [x] Webpack 4 compatible release of HtmlWebpackPlugin
- [x] Webpack 4 compatible release of SwPrecacheWebpackPlugin
- [x] Webpack 4 compatible release of WebpackManifestPlugin
- [x] Update README
- [x] Update WebpackDevServerUtils
- [x] Update InterpolateHtmlPlugin
- [x] Update ModuleScopePlugin
- [x] Update WatchMissingNodeModulesPlugin
- [x] Move UglifyJS options to webpack 4 optimize
- [x] Move InterpolateHtmlPlugin to make it tapable on HtmlWebpackPlugin
- [x] vendor splitting via splitChunks.splitChunks (https://twitter.com/wSokra/status/969633336732905474)
- [x] long term caching via splitChunks.runtimeChunk (https://twitter.com/wSokra/status/969679223278505985)
- [x] Make sure process.env.NODE_ENV is proxied correctly to `react-error-overlay`
- [x] Implicit webpack.NamedModulesPlugin in dev config as its default in webpack 4
- [x] Disable webpack performance hints as we have our own filesize reporter
- [x] Replace ExtractTextPlugin with MiniCssExtractPlugin
- [x] Switch to css whole file minification via OptimizeCSSAssetsPlugin rather than per module css minification to gain performance

* Bump dependencies

* Use a more sensible way to compile error overlay

* Keep old chalk for global CLI

* Update dependencies in react-scripts

* Add first pass of working dependencies for babel-preset-react-app and react-scripts

* Bump more dependency versions

* Adjust more versions and edit fix options

* Restore functionality of old preset

* Disable Uglify in iframe webpack

* Apply prettier

* Re-enable cache in dev and clean deps

* Lock packages and move babel/core to dep in preset

* Bump babel-jest

* Re-enable uglify

* Nest forceAllTransforms correctly in webpack config

* Install babel-core bridge for jest

* Add jest-cli and babel-core bridge to make tests in react-error-overlay pass

* Re-enable transform-dynamic-import

* Add dynamic import syntax support back

* Use new babel in kitchensink

* Transform modules in test

* Revert "Transform modules in test"

This reverts commit 539e46a1.

* Attempt fix for ejected tests

* try this

* Add regenerator back

* Bump babel deps to beta.34

* Remove bad files

* Use default when requiring babel transform plugin

* Bump deps

* Try the fix?

* Oopsie

* Remove some weird things

* Run Babel on react-error-overlay tests

* Try fixing kitchensink

* Use new API for codeFrame

* Add missing (?) babelrc

* Maybe this helps?

* Maybe fix mocha

* I shouldn't have deleted this 

* Use production React version

* We cannot strip our own checks if production

* Keep the sourcemap during minify

* Prevent devtools pollution

* Add some comments

* sigh

* Make error overlay to run in the context of the iframe

* Configure webpack to build the entire package

* Remove inline raw-loader config

* Configure watch mode for error-overlay webpack build

* Add polyfills to the error-overlay iframe script

* Add header comment

* Configure to fail CI on error or warning

* Suppress flow-type error on importing iframe-bundle

* Change webpack to a dev dependency and pin some versions

* Disable webpack cache

* Update license headers to MIT