several changes:

- by popular demand I have changed the behaviour of the --delete
option. It should now work as "expected" for even those people silly
enough not to read the man page. rsync will now only look for
candidate files/directories to delete in directories that are
explicitly transferred from the sender
- updated the README a bit
- try to fail a bit more gracefully when rsync runs out of disk
space. I don't think this issues is fully resolved yet