* lots of cleanup, more to come
* made the Linux version work and switched to GNU/coreutils
* introduced undocumented DEBUG variable
* introduced do_log, not sure if want to use exit later on
* added sha224, sha384
* added dummy functions for darwin, freebsd, solaris

	modified:   checksum_files.sh
Signed-off-by: Christian Kujau <github@nerdbynature.de>