-- fix up docs, move all to POD, in relevant classes.

-- tool to clean digestcache, based on prefixes, looking for files that no longer
   exist or have new mtimes, etc?  or keep track of "last used" date
   field in the digestcache and just delete things that are too old?
   but then no longer just a dictionary.  SQLite would work, but we'd ideally
   like lots of dumber cache mechanisms.  maybe a ->clean method is optional?
   then a memcached backend/etc doesn't have to use it.

-- ionice stuff.  network nice stuff.

-- leaking 3 /tmp files after each run

-- make tests pass without 'noatime' mount option

-- --ignore-debian-files option (if managed by a package management
   system (and not an unmodified conffile), don't back it up)

-- reuse tempfiles in Chunk.pm as Restore.pm does

-- restoring from existing config file.

-- better test coverage.  currently at 84%.  should ignore
   test coverage of test modules.  move Brackup::Test to
   t/lib/ probably

-- should do TODOs in code.  :)
