Mute the MSVC 4251 warning for 'WindowNavigator'
Mute the MSVC 4251 warning for 'WindowNavigator'

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