Prior to 7.4, occt had a 'using namespace std' in a header file that
was polluting dependent projects. They have since fixed it and so these
changes are required.
With DisplayLists being deprecated in GL and VBO and VAO becoming standard it's best to standardize on using the osgUtil::MeshOptimizers instead of TripStrupVisitor
Added geometry.setUseVertexBufferObjects(true) to geometry set up for improved performance.
Refactored the color set up so that by default it assigns just a single color to the geometry to improve performance.