Cache loaded items

This is a somewhat different solution for improving the
performance of the welcome screen. It has the added benefit
of caching loaded items while still retaining a decent
performance.

Change-Id: I9927a90f1b7de5bb06c43b16dc80cb2afec3f8ad
Reviewed-by: Ulf Hermann <ulf.hermann@digia.com>
Reviewed-by: Eike Ziller <eike.ziller@digia.com>