Swap/change superclass relationships

[treeowl]

Currently,

class Functor f => Semialign f
class Semialign f => Zip f
class Zip f => Unzip f

But this makes no sense! Every Functor can unzipWith (perhaps badly), but not every Functor can zipWith. I would recommend doing something like this instead:

class Functor f => Unzip f
class Unzip f => Semialign f
class Semialign f => Zip f

[phadej]

FWIW, unzip could very well be part of every Functor. There's an argument that it can be efficient.

I don't see much value in doing swapping atm.