Use an autorelease pool in member expansion

Otherwise, we would hold one ldap connection for each member of a group.
And close them all later. With large groups, we could hit the open file limit
(or the open file limit of the ldap server).

Fixes #2256

SoObjects/SOGo/SOGoGroup.m

@@ -57,6 +57,7 @@
 #include "SOGoGroup.h"
 
 #import <Foundation/NSArray.h>
+#import <Foundation/NSAutoreleasePool.h>
 #import <Foundation/NSDictionary.h>
 #import <Foundation/NSString.h>
 
@@ -224,6 +225,7 @@
   NSDictionary *d;
   SOGoUser *user;
   NSArray *o;
+  NSAutoreleasePool *pool;
   int i, c;
 
   if (!_members)
@@ -259,7 +261,8 @@
 
           // We add members for whom we have their associated DN
           for (i = 0; i < [dns count]; i++)
-            {
+            { 
+              pool = [NSAutoreleasePool new];
               dn = [dns objectAtIndex: i];
               login = [um getLoginForDN: [dn lowercaseString]];
               user = [SOGoUser userWithLogin: login  roles: nil];
@@ -268,11 +271,13 @@
                   [logins addObject: login];
                   [_members addObject: user];
                 }
+              [pool release];
             }
 
           // We add members for whom we have their associated login name
           for (i = 0; i < [uids count]; i++)
             {
+              pool = [NSAutoreleasePool new];
               login = [uids objectAtIndex: i];
               user = [SOGoUser userWithLogin: login  roles: nil];
               
@@ -281,6 +286,7 @@
                   [logins addObject: login];
                   [_members addObject: user];
                 }
+              [pool release];
             }