FIX: Implement / fix Tree::ensureItemIsVisible (damned amateurs).
FIX: Implement / fix Tree::ensureItemIsVisible (damned amateurs).

OpenTechEngine/CEGUI,ruleless/CEGUI,ruleless/CEGUI,OpenTechEngine/CEGUI,ruleless/CEGUI,ruleless/CEGUI,OpenTechEngine/CEGUI,OpenTechEngine/CEGUI