The attached patch adds assertUnequal support to
HUnit (I am new to Haskell, less than a week of
experience, please, check the code carefully).
Note: I was not able to run the functions I wrote
when I added them to HUnit itself (I couldn't figure
it out how to compile HUnit, I used HUnit from
Ubuntu's packages for my project and the functions I
added to HUnit where working on my own module).