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/compose/components/autosuggest_account.js

@@ -0,0 +1,26 @@
+import React from 'react';
+import Avatar from '../../../components/avatar';
+import DisplayName from '../../../components/display_name';
+import ImmutablePropTypes from 'react-immutable-proptypes';
+import ImmutablePureComponent from 'react-immutable-pure-component';
+
+class AutosuggestAccount extends ImmutablePureComponent {
+
+  render () {
+    const { account } = this.props;
+
+    return (
+      <div className='autosuggest-account'>
+        <div className='autosuggest-account-icon'><Avatar src={account.get('avatar')} staticSrc={account.get('avatar_static')} size={18} /></div>
+        <DisplayName account={account} />
+      </div>
+    );
+  }
+
+}
+
+AutosuggestAccount.propTypes = {
+  account: ImmutablePropTypes.map.isRequired
+};
+
+export default AutosuggestAccount;