Release 5.0.0-alpha3 (#476)

* 95 additional icons; including file types, directional, and some existing and new brand icons
* Wrong content type in generated CSS #458
* Removal of query string from static resources #458
* SVG font ID's are incorrect in webfont implementation #474

svgs/regular/level-down-alt.svg

@@ -0,0 +1,9 @@
+<!-- Generator: Adobe Illustrator 21.1.0, SVG Export Plug-In  -->
+<svg version="1.1"
+	 xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:a="http://ns.adobe.com/AdobeSVGViewerExtensions/3.0/"
+	 x="0px" y="0px" width="320px" height="512px" viewBox="0 0 320 512" style="enable-background:new 0 0 320 512;"
+	 xml:space="preserve">
+<path d="M296.64,412.326l-96.16,96.16c-4.686,4.687-12.285,4.686-16.97,0l-96.156-96.156c-7.536-7.536-2.198-20.484,8.485-20.485
+	L164,391.843V56H64c-3.183,0-6.235-1.264-8.485-3.515l-32-32C15.955,12.926,21.309,0,32,0l164,0c13.255,0,24,10.745,24,24v367.842
+	l68.154-0.001C298.78,391.84,304.22,404.746,296.64,412.326z"/>
+</svg>