Add scripts for testing compatability with hackage packages
So far just a test that all the non-trivial Setup.(l)hs scripts compile. This only tests the latest versions, though if one were to download a complete archive then one could test them all. To speed up the check we skip Setup.hs scripts that have fewer than 22 words. Below this cutoff there are no custom hooks and it catches the great majority of scripts which greatly speeds up the check.