Change rasterizer member variable in SoftwareRenderer from unique_ptr to stack-allocated
Change rasterizer member variable in SoftwareRenderer from unique_ptr to stack-allocated

I think I originally used a unique_ptr there because Rasterizer is not default-constructible, but of course we can still use a stack-allocated member, if we initialise it directly in the constructor.

patrikhuber/eos,patrikhuber/eos,patrikhuber/eos