Improve long dropdown menu lists (#2108)

Dropdown menus with lots of entries were a bit difficult to use …
Set max height to 75% of Viewport-height and enabled scrolling

app/views/helpers/index/normal/entry_bottom.phtml

@@ -42,7 +42,7 @@
 			<a class="dropdown-toggle" href="#dropdown-labels-<?php echo $this->entry->id();?>"><?php
 				echo _t('index.menu.tags');
 			?></a>
-			<ul class="dropdown-menu">
+			<ul class="dropdown-menu dropdown-menu-scrollable">
 				<li class="dropdown-close"><a href="#close">❌</a></li>
 				<!-- Ajax -->
 			</ul>

p/themes/base-theme/template.css

@@ -230,6 +230,11 @@ a.btn {
 	background: #fff;
 	border: 1px solid #aaa;
 }
+.dropdown-menu-scrollable {
+	max-height: 75vh;
+	overflow-x: hidden;
+	overflow-y: auto;
+}
 .dropdown-header {
 	display: block;
 }