Changelog for hashed-storage-0.5.4

hashed-storage 0.4.0 ==================== - Index now uses a 32-byte representation for sha256 hashes, instead of a 64-byte ascii-hex (base16) encoding. - New module Storage.Hashed.Hash that exports a new incarnation of Hash data type and a number of utilities. - The Tree type is overloaded over a monad type and is not bound to IO monad anymore. - Index has been streamlined, the API has improved safety and the code has been extensively optimised. - Support for creating new hashed trees with the <size>-<hash> format used in darcs 2.0.2 and newer has been dropped.