GUAC-1126: Restore disconnect button within Guacamole menu.

guacamole/src/main/webapp/app/client/styles/menu.css

@@ -81,6 +81,23 @@
     
 }
 
+.menu-content .header button.close {
+
+    margin: 0;
+    padding: 0;
+    min-width: 3em;
+
+    border: none;
+    box-shadow: none;
+    background: none;
+
+    background-image: url('images/x.png');
+    background-size: 1em;
+    background-repeat: no-repeat;
+    background-position: center;
+
+}
+
 .menu-body {
 
     -ms-flex: 1 1 auto;

guacamole/src/main/webapp/app/client/templates/client.html

@@ -59,6 +59,7 @@
             <!-- Stationary header -->
             <div class="header">
                 <h2>{{client.name}}</h2>
+                <button class="close" ng-click="disconnect()"></button>
                 <guac-user-menu></guac-user-menu>
             </div>