Put function pragma after the functions.

Improve quickchecks.

Added QuickCheck test.

Clarify doctest for split.

Format Cabal file a bit.

Add Stack build file.

Ignore Criterion reports.

Use `nf` instead of `whnf`.

Add benchmarks.

Move tests to a dedicated directory.

Make gfEval point-free.

Fix indentation.

Expand lambda.

Fix inlining for gfExp and gfDiv.

Move gfYIntercept to foldr.