Fixed a cast issue in OpenGLSystem::Update

There was an issue with casting and an exception wasn't being thrown
when it should have.

Also adding test drawing code for GLIcoSphere. GLIcoSphere is in the
next commit.
Add GLIcoSphere component

GLIcoSphere is a icosahedron that can refined to any level to produce a
icosphere. The larger the refinement level the more round the sphere is.

The transform operations starting with GLIcoSphere has been moved to
GLTransform.