Site Service: expose methods to get group names and available site roles

git-svn-id: https://svn.alfresco.com/repos/alfresco-enterprise/alfresco/HEAD/root@10479 c4b6b30b-aa2e-2d43-bbcb-ca4b014f7261

source/java/org/alfresco/repo/site/SiteService.java

@@ -154,6 +154,13 @@ public interface SiteService
      */
     boolean hasContainer(String shortName, String componentId);
     
+    /**
+     * Gets a list of all the currently available roles that a user can perform on a site
+     * 
+     * @return  List<String>    list of availble roles
+     */
+    List<String> getSiteRoles();
+     
     /**
      * Gets the sites group.  All members of the site are contained within this group.
      *