WelcomeScreen: fix fuzzy fonts in the side bar

Use native text rendering to get crisp fonts

Change-Id: I75ca9ae323f2e4bd60e080cdcc2a6d90f0234c33
Reviewed-by: Jens Bache-Wiig <jens.bache-wiig@digia.com>
Reviewed-by: Thomas Hartmann <Thomas.Hartmann@digia.com>