v0.4.0.0

http://hackage.haskell.org/package/manifolds-0.4.0.0

The two most basic classes – Semimanifold and PseudoAffine – have been put in a small standalone package, manifolds-core. The main reason it to allow linearmap-category to depend on these classes, so we now have a proper hierarchy in which every vector space is also a manifold.