UI: Make dashboard navbar and footer full-width (#6013)

* UI: Make dashboard navbar full-width

* more tweaks: full-width footer and consistent padding

* fix page layout causing unneccesary scrollbars on small pages

templates/user/dashboard/navbar.tmpl

@@ -1,4 +1,4 @@
-<div class="ui container">
+<div class="dashboard-navbar">
 	<div class="ui secondary stackable menu">
 		<div class="item">
 			<div class="ui floating dropdown link jump">