Ignore non-visible included groups when listing members recursively

When the members of a group are listed via REST with the 'recursive'
option ignore those included groups which are not visible to the
calling user. This is better than failing completely as we do
currently and is consistent with how included external groups are
handled (they are also ignored).

Change-Id: I02b2213573b2647582bddcdcab374c672308bc89
Signed-off-by: Edwin Kempin <edwin.kempin@sap.com>
diff --git a/Documentation/rest-api-groups.txt b/Documentation/rest-api-groups.txt
index b24616f..4b17434 100644
--- a/Documentation/rest-api-groups.txt
+++ b/Documentation/rest-api-groups.txt
@@ -638,6 +638,9 @@
 To resolve the included groups of a group recursively and to list all
 members the parameter `recursive` can be set.
 
+Members from included external groups and from included groups which
+are not visible to the calling user are ignored.
+
 .Request
 ----
   GET /groups/834ec36dd5e0ed21a2ff5d7e2255da082d63bbd7/members/?recursive HTTP/1.0