- Update design-notes

Create:

--owner
--group

- dump file data to a CDB? for incremental backups
  - Store timestamp of start of backup (in "" record)
  - Store dev/ino (key) of each listed file and each directory

- Listed incremental backup:
  - Look up last timestamp in CDB
  - From tar:
     The file FILE, which is archive independent, contains the date it
     was last modified and a list of devices, inode numbers and directory
     names.  `tar' will archive files with newer mod dates or inode change
     times, and directories with an unchanged inode number and device but a
     changed directory name.

Extract:

--modification-time
--[no-]same-owner
--[no-]same-permissions / --preserve-permissions

- Validate the SOA parameters.

- unhandled file types:
    b -- block device
    c -- character device

- Incremental restore:
  - For each directory listed in the archive:
    - Unlink files in the destination not listed in the directory record
    - Warn about files not present in the destination