Add autorelease pool for cocoa plugin creation.

Prevents mem leaks at startup on 10.6.

Change-Id: I5f8b72c54ab396ee0ec2e47320163a6a342b78f1
Reviewed-by: Gabriel de Dietrich <gabriel.dedietrich@digia.com>

src/plugins/platforms/cocoa/main.mm

@@ -59,6 +59,9 @@ public:
 QPlatformIntegration * QCocoaIntegrationPlugin::create(const QString& system, const QStringList& paramList)
 {
     Q_UNUSED(paramList);
+
+    QCocoaAutoReleasePool pool;
+
     if (system.toLower() == "cocoa")
         return new QCocoaIntegration;