* Remove unused (and broken) test files
* Make default.nix expose pinned nixpkgs
Also make `nixpkgs/default.nix` just an attribute set of sources.
This is simpler, and consistent with what e.g. `niv` does.
* Add backwards compatibility shim, and version argument to allow evolution in future
* Fix some missed things
* Fix and improve quickstart
* Updated the haskell.nix imports to overlay style
Some of the examples in the documentation were still passing an empty
set to the haskell.nix imports but this is no longer valid because the
import now results in a set rather than a function.
* Fix overlay imports in docs
Import an overlayed nixpkgs rather than just the overlay.
Thanks to angerman for noticing this error.
Hamish Mackenzie
Michael Peyton Jones
Toon Nolten
Rodney Lorrimar