lens-core

Cabal 2.2 allows reexported modules, which will eventually allow us to consider splitting lens into smaller pieces. Cabal 3.4 allows multiple public sub-libraries in a package Which may be a better plan, to avoid hackage namespace pollution. I'm claiming this name to avoid rampant namespace confusion between lens:core and lens-core in the latter scenario and to allow progress on the former scenario. For now, use lens.