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/reducers/status_lists.js

@@ -0,0 +1,39 @@
+import {
+  FAVOURITED_STATUSES_FETCH_SUCCESS,
+  FAVOURITED_STATUSES_EXPAND_SUCCESS
+} from '../actions/favourites';
+import Immutable from 'immutable';
+
+const initialState = Immutable.Map({
+  favourites: Immutable.Map({
+    next: null,
+    loaded: false,
+    items: Immutable.List()
+  })
+});
+
+const normalizeList = (state, listType, statuses, next) => {
+  return state.update(listType, listMap => listMap.withMutations(map => {
+    map.set('next', next);
+    map.set('loaded', true);
+    map.set('items', Immutable.List(statuses.map(item => item.id)));
+  }));
+};
+
+const appendToList = (state, listType, statuses, next) => {
+  return state.update(listType, listMap => listMap.withMutations(map => {
+    map.set('next', next);
+    map.set('items', map.get('items').concat(statuses.map(item => item.id)));
+  }));
+};
+
+export default function statusLists(state = initialState, action) {
+  switch(action.type) {
+  case FAVOURITED_STATUSES_FETCH_SUCCESS:
+    return normalizeList(state, 'favourites', action.statuses, action.next);
+  case FAVOURITED_STATUSES_EXPAND_SUCCESS:
+    return appendToList(state, 'favourites', action.statuses, action.next);
+  default:
+    return state;
+  }
+};