QMatrix4x4 accepts data in row-major order, but returns them in
column-major order, which is not documented and because of that
I expected them to be in row-major order.
This commit fixes it and rewrites the shaders to apply the matrix
multiplications in the right order.
REVIEW: 100759
A color can be specified to render the geometry of the VBO.
For legacy painting glColor is used, for shader a uniform is set.
In order to allow rendering without texcoords, it is possible to pass
a null pointer as texcoords.
Shader added to scene which just renders a colored geometry without texturing.
