Killing or resurrecting version tags for good

[Edward Z. Yang]

Excerpts from Mikhail Glushenkov's message of 2014-07-26 23:44:39 +0100:
> IIRC, Duncan wants to remove version tags both from Cabal and
> Data.Version. So perhaps it's time to deprecate them.

My question here is orthogonal to the question of deprecation:
if we are deprecating them, but not removing them, we should
still print the tags while we still ostensibly support them!

Edward