Moving basic functions

[David Luposchainsky]

So to sum it up, the current consensus seems to be the following:

1. Unanimously supported: Move "void" from Control.Monad to
Data.Functor; re-export the function from Control.Monad for compatibility.

2. Scrap the tuple business. Modifying Prelude is not a good idea, and
an irrefutable swap is based on principles that may require their own
proposal (call it the "forceSwap" issue or something).

3. Unanimously supported: Move "($>) = flip (<$)" from Control.Comonad
to Data.Functor.

Greetings,
David