Better Representable instance for List.
Add support for Records.
Adds the BooleanAlgebra interface, as the operations make sense in other domains.
Renames describe → to-string (Fixes #63)

--HG--
extra : amend_source : 9f8df22bb62f5cf9c5bb3213aa53d7b30b5b8c65
Better error messages for FFI
Provides BooleanAlgebra operations for Tasks.