Fixing #401

Resolving regression caused by #393, and re-introduced original
resize handler method used by @petergood -- placing it behind
lodash .debounce should appease @pitaj's concerns, but I frankly
see no other way to have this feature but also fix cases where
the header is not at the top of the page.

less/header.less

@@ -242,10 +242,6 @@
 			margin-left: -30px;
 		}
 	}
-
-	@media (min-width: @screen-md-min) {
-		top: 0px !important;
-	}
 }
 
 .breadcrumb {

lib/persona.js

@@ -8,11 +8,25 @@ $(document).ready(function() {
 	setupEditedByIcon();
 	setupMobileMenu();
 	setupQuickReply();
+	configureNavbarHiding();
 
-	$(".navbar-fixed-top").autoHidingNavbar({
-		showOnBottom: false
+	require(['lodash'], function (_) {
+		$(window).on('resize', _.debounce(configureNavbarHiding, 200));
 	});
 
+	function configureNavbarHiding () {
+		var navbarEl = $(".navbar-fixed-top");
+		navbarEl.autoHidingNavbar('destroy');
+		navbarEl.css('top', '');
+
+		var env = utils.findBootstrapEnvironment();
+		if (env === 'xs' || env ==='sm') {
+			navbarEl.autoHidingNavbar({
+				showOnBottom: false,
+			});
+		}
+	};
+
 	function setupNProgress() {
 		$(window).on('action:ajaxify.start', function() {
 			NProgress.set(0.7);

yarn.lock

@@ -2,10 +2,10 @@
 # yarn lockfile v1
 
 
-pulling@^1.1.0:
-  version "1.1.0"
-  resolved "https://registry.yarnpkg.com/pulling/-/pulling-1.1.0.tgz#d1460833b623fedcb73c71efb4cbb6824d990749"
+pulling@^1.1.1:
+  version "1.1.1"
+  resolved "https://registry.yarnpkg.com/pulling/-/pulling-1.1.1.tgz#948c72ec75d76c4ff41d6cec1ef1208c8d9d18f6"
 
-striptags@^3.1.0:
-  version "3.1.0"
-  resolved "https://registry.yarnpkg.com/striptags/-/striptags-3.1.0.tgz#763e534338d9cf542f004a4b1eb099e32d295e44"
+striptags@^3.1.1:
+  version "3.1.1"
+  resolved "https://registry.yarnpkg.com/striptags/-/striptags-3.1.1.tgz#c8c3e7fdd6fb4bb3a32a3b752e5b5e3e38093ebd"