merge r11152 from branch 2.2 to trunk

feature 1622 added: pwg.categories.getList is now able to return a tree with
the new "tree_output" option. Only compatible with json/php output formats.



git-svn-id: http://piwigo.org/svn/trunk@11155 68402e56-0260-453c-a942-63ccdbb3a9ee

ws.php

@@ -81,8 +81,9 @@ function ws_addDefaultMethods( $arr )
         'cat_id' => array('default'=>0),
         'recursive' => array('default'=>false),
         'public' => array('default'=>false),
+        'tree_output' => array('default'=>false),
       ),
-      'retrieves a list of categories' );
+      'retrieves a list of categories (tree_output option only compatible with json/php output format' );
 
   $service->addMethod('pwg.images.addComment', 'ws_images_addComment',
       array(