- check "simulate" patch: http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=602837

- in incremental backup, do not create a directory hierarchy when no file at all was modified inside it
  (e.g. store the dir entries in a stack until we find the first file which has to be stored, 
   then create all dirs in the stack. If no file found, clean the stack and do not create any dir in the archive)
- implement a way for restoring backups
- backup as "cp -R" without creating a .tar file

- option to compress the complete tar file _after_ finish-slice
