Complete the split DistortedObject -> (DistortedTexture,DistortedEffectQueue)
Rename various classes; fix a bug in Around the World.
Major change in API: separate the GRID from DistortedObject; completely remove classes derived from DistortedObject.
Make the effect Center be always 3D.
Unify Effects3D and Matrix3D (still incomplete!)
Minor stuff
Tidy up 'Matrix3D'
Skeleton of the new App: Vertex3D. So far just a copy of Matrix3D.
Rename Effects3D to Matrix3D