- When --max-delete is exceeded, we now count how many deletions

- When --max-delete is exceeded, we now count how many deletions
  would have happend, warn about the number skipped, and set
  io_error to IOERR_DEL_LIMIT.
- When dry_run > 1 (which indicates that the destinationdir is
  missing), skip deletions in that dir.  This fixes a bug in a
  copy that is creating the destination dir w/--delete enabled.