Support code for reading and manipulating hashed file storage (where
each file and directory is associated with a cryptographic hash, for
corruption-resistant storage and fast comparisons).

The supported storage formats include darcs hashed pristine, a plain
filesystem tree and an indexed plain tree (where the index maintains
hashes of the plain files and directories).

After uninstalling, run this command to unregister the package from
the ghc package database:   ghc-pkg recache
