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/link_header.js

@@ -0,0 +1,33 @@
+import Link from 'http-link-header';
+import querystring from 'querystring';
+
+Link.parseAttrs = (link, parts) => {
+  let match = null
+  let attr  = ''
+  let value = ''
+  let attrs = ''
+
+  let uriAttrs = /<(.*)>;\s*(.*)/gi.exec(parts)
+
+  if(uriAttrs) {
+    attrs = uriAttrs[2]
+    link  = Link.parseParams(link, uriAttrs[1])
+  }
+
+  while(match = Link.attrPattern.exec(attrs)) { // eslint-disable-line no-cond-assign
+    attr  = match[1].toLowerCase()
+    value = match[4] || match[3] || match[2]
+
+    if( /\*$/.test(attr)) {
+      Link.setAttr(link, attr, Link.parseExtendedValue(value))
+    } else if(/%/.test(value)) {
+      Link.setAttr(link, attr, querystring.decode(value))
+    } else {
+      Link.setAttr(link, attr, value)
+    }
+  }
+
+  return link
+};
+
+export default Link;