Haskell testing framework, rerun support

 This ingredient adds the ability to run tests by first filtering the
 test tree based on the result of a previous test run.
 For example, you can use this to run only those tests that failed
 in the last run, or to run only tests that have been added since
 tests were last ran.
 .
 This package provides a library for the Haskell programming language.
 See http://www.haskell.org/ for more information on Haskell.