Fix for unwind (3aa7b171b4) means that it's no longer necessary to manually eta-expand super-combinators

Short version: Eta-reduced super-combinators used to not work and now they do.
Long version: We used to have to do this:

Cons x xs = Pack{3,2} x xs;

Now we can just do:

Cons = Pack{3, 2};

The actual internal Pack operator cannot be partially applied, but the compiler
generates a pseudo-Pack that wraps the operator in an (automatically) eta-
expanded super-combinator.

This has been working for a while now, but I'm just now removing manual eta-
expansion from the examples and README.