* If a dir is listed in $keep_dirs it won't be removed (anyway any
directory that is not empty won't either).
* If a config file hasn't been modified (SHA256 hash matches) the
file will be removed, otherwise it won't be removed.
There's still missing support to handle new configuration files when
there's an existing file, but will do later.
--HG--
extra : convert_revision : 448af95876fc7a47da07a9a910d6111047f72271