Since hoogle usually works by downloading some databases or source
files from Hackage/HaskellWiki, and in Debian we want a hermetic
build/install, the `debian/files_hoogle/update_hoogle` script tries to
trick hoogle into working fully offline.

This doesn't offer the full functionality of hoogle (e.g. full package
list is not available), but we do have full local indexing (based on
what packages are installed).

 -- Iustin Pop <iustin@debian.org>, Sun, 21 Sep 2014 22:06:10 +0200