GUAC-1053: Clean up display of mouse modes.

guacamole/src/main/webapp/app/settings/styles/mouse-mode.css

@@ -20,6 +20,14 @@
  * THE SOFTWARE.
  */
 
+.preferences .mouse-mode .choices {
+    text-align: center;
+}
+
+.preferences .mouse-mode .choice {
+    display: inline-block;
+}
+
 .preferences .mouse-mode .choice .figure {
     display: inline-block;
     vertical-align: middle;
@@ -33,3 +41,7 @@
     max-width: 320px;
     margin: 1em auto;
 }
+
+.preferences .mouse-mode .caption {
+    text-align: left;
+}