The point of this change is to move towards having a single vertex class with known properties (including normal). This makes it simpler to write code which uses the vertices because we always know which properties are present. This will probably be useful when working with vertex buffer objects.
The example now uses OpenGL 3 features like Vertex Array Objects and uses
no immediate mode stuff. Qt5 is used for some features like matrices and
shaders.
There is now no dependency on GLEW either.
Replaced 'SurfaceVertex' with PositionMaterial and PositionMaterialNormal classes.
Different surface extractors can now work with different vertex types.
