GUACAMOLE-5: Generalize and clean the guacGroupList directive such that arbitrary GroupListItem types can be supported.

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

@@ -25,8 +25,10 @@
             <guac-group-list
                 context="context"
                 connection-groups="filteredRootConnectionGroups"
-                connection-template="'app/home/templates/connection.html'"
-                connection-group-template="'app/home/templates/connectionGroup.html'"
+                templates="{
+                    'connection'       : 'app/home/templates/connection.html',
+                    'connection-group' : 'app/home/templates/connectionGroup.html'
+                }"
                 page-size="20"></guac-group-list>
         </div>