Add GHC.Generics for LargeHashable
Add GHC.Generics for LargeHashable

For that I added a LargeHashable' class implementing the hashing
of generic representations and a default implementation for
LargeHashable.

Example code:

data Test = Foo | Bar Int Bool | Baz Bool deriving Generic
instance LargeHashable Test
largeHash md5HashAlgorithm (Baz True)
largeHash md5HashAlgorithm (Bar 2 True)
largeHash md5HashAlgorithm Foo

factisresearch/large-hashable,factisresearch/large-hashable,sternenseemann/large-hashable,sternenseemann/large-hashable