Frontent dev env (#247)

* Added frontend development files/environment

* More items-categories related removals

* Improvements in pages templates (inc. static pages)

* Improvements in video player

* Added empty home page message + cta

* Updates in media, playlist and management pages

* Improvements in material icons font loading

* Replaced media & playlists links in frontend dev-env

* frontend package version update

* chnaged frontend dev url port

* static files update

* Changed default position of theme switcher

* enabled frontend docker container

static/js/_commons.js.LICENSE.txt

@@ -0,0 +1,46 @@
+/*
+object-assign
+(c) Sindre Sorhus
+@license MIT
+*/
+
+/*!
+ * The buffer module from node.js, for the browser.
+ *
+ * @author   Feross Aboukhadijeh <feross@feross.org> <http://feross.org>
+ * @license  MIT
+ */
+
+/** @license React v0.20.2
+ * scheduler.production.min.js
+ *
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+/** @license React v17.0.2
+ * react-dom.production.min.js
+ *
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+/** @license React v17.0.2
+ * react.production.min.js
+ *
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+/**!
+ * Sortable 1.13.0
+ * @author	RubaXa   <trash@rubaxa.org>
+ * @author	owenm    <owen23355@gmail.com>
+ * @license MIT
+ */