Replace sprockets/browserify with Webpack (#2617)

* Replace browserify with webpack

* Add react-intl-translations-manager

* Do not minify in development, add offline-plugin for ServiceWorker background cache updates

* Adjust tests and dependencies

* Fix production deployments

* Fix tests

* More optimizations

* Improve travis cache for npm stuff

* Re-run travis

* Add back support for custom.scss as before

* Remove offline-plugin and babili

* Fix issue with Immutable.List().unshift(...values) not working as expected

* Make travis load schema instead of running all migrations in sequence

* Fix missing React import in WarningContainer. Optimize rendering performance by using ImmutablePureComponent instead of
React.PureComponent. ImmutablePureComponent uses Immutable.is() to compare props. Replace dynamic callback bindings in
<UI />

* Add react definitions to places that use JSX

* Add Procfile.dev for running rails, webpack and streaming API at the same time

app/javascript/mastodon/features/notifications/components/setting_toggle.js

@@ -0,0 +1,21 @@
+import React from 'react';
+import PropTypes from 'prop-types';
+import ImmutablePropTypes from 'react-immutable-proptypes';
+import Toggle from 'react-toggle';
+
+const SettingToggle = ({ settings, settingKey, label, onChange, htmlFor = '' }) => (
+  <label htmlFor={htmlFor} className='setting-toggle__label'>
+    <Toggle checked={settings.getIn(settingKey)} onChange={(e) => onChange(settingKey, e.target.checked)} />
+    <span className='setting-toggle'>{label}</span>
+  </label>
+);
+
+SettingToggle.propTypes = {
+  settings: ImmutablePropTypes.map.isRequired,
+  settingKey: PropTypes.array.isRequired,
+  label: PropTypes.node.isRequired,
+  onChange: PropTypes.func.isRequired,
+  htmlFor: PropTypes.string
+};
+
+export default SettingToggle;