Fixed image manager loading error. CEGUI now starts with std::string as CEGUI::String
Fixed image manager loading error. CEGUI now starts with std::string as CEGUI::String

It's never a good idea to pass a const ref to a temporary string and then reference it
back and use it.

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