Switch to external auth API.

guacamole/pom.xml

@@ -85,6 +85,14 @@
             <scope>compile</scope>
         </dependency>
 
+        <!-- Guacamole Authentication API -->
+        <dependency>
+            <groupId>net.sourceforge.guacamole</groupId>
+            <artifactId>guacamole-common-auth</artifactId>
+            <version>0.5.0</version>
+            <scope>compile</scope>
+        </dependency>
+
         <!-- Guacamole JavaScript API -->
         <dependency>
             <groupId>net.sourceforge.guacamole</groupId>