Bug 994280 - Improve badged button for Australis. r=enn

- moved badged button XBL from browser to toolkit
 - made the XBL applied by CSS class instead of button's type
 - added australis look & feel to badged button
 - fixed OS X badge position

browser/components/customizableui/CustomizableWidgets.jsm

@@ -915,7 +915,7 @@ const CustomizableWidgets = [
       node.setAttribute("id", this.id);
       node.classList.add("toolbarbutton-1");
       node.classList.add("chromeclass-toolbar-additional");
-      node.setAttribute("type", "badged");
+      node.classList.add("badged-button");
       node.setAttribute("label", CustomizableUI.getLocalizedProperty(this, "label"));
       node.setAttribute("tooltiptext", CustomizableUI.getLocalizedProperty(this, "tooltiptext"));
       node.setAttribute("removable", "true");