From Aurelien Albert, "I'm working with OSG and a customer low-level OpenGL library.

To make easier "lazy apply" on the customer OpenGL shaders, the easiest way was to add an accessor to current OSG state's UniformMap.

I've also added accessors for modes and texture, since it could be usefull in the same way.

All methods are const, so I think there is no side-effects."