GUACAMOLE-5: Clean up header and dropdown style.

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

@@ -65,8 +65,8 @@
 
     cursor: default;
     margin: 0;
-    min-width: 2in;
     padding: 0.5em;
+    padding-right: 2em;
 
     -ms-flex: 0 0 auto;
     -moz-box-flex: 0;
@@ -98,7 +98,8 @@
     position: absolute;
     top: 100%;
     right: 0;
-    left: -1px;
+    min-width: 100%;
+    white-space: nowrap;
 
     background: #EEE;
     box-shadow: 0 2px 2px rgba(0, 0, 0, 0.125);