Proposal: derive Typeable for Data.Monoid types

[Simon Peyton Jones]

| You can't enable it everywhere in base due to module-import cycles (you
| need to import Data.Typeable before you can AutoDeriveTypeable a
| module), but other than that, the plan is to enable it wherever possible
| in base.

Is someone going to execute on that intention?  Thanks!

Generally speaking, for every data type in base
- either AutoDeriveTypeable should be on
- or there should be a standalone deriving clause in Typeable
  (so that the instance isn't an orphan)

Simon