Add CEGUI_INCLUDE_DIRS parent dir only for CEGUI 0.8+
Add CEGUI_INCLUDE_DIRS parent dir only for CEGUI 0.8+

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