BETA 8 TODO
- keys expire
- sunion ssub
- write integers in a special way on disk (and on memory?)
- compact types for disk storing of short strings (no 4 bytes overhead!)
- network layer stresser in test in demo
- maxclients directive
- check 'server.dirty' everywere
- replication tests
- command line client. If the last argument of a bulk command is missing get it from stdin. Example:
    $ echo "bar" | redis-client SET foo
    $ redis-client SET foo bar
    $ redis-client GET foo
    bar
    $
- Make Redis aware of the memory it is using thanks to getrusage() and report this info with the INFO command.
- INFO command: clients, slave/master, requests/second in the last N seconds, memory usage, uptime, dirty, lastsave

FUTURE

ROLLBACK command:

    ROLLBACK UNSET x
    SET x 10
    EXPIRE x 3600
    COMMIT

    (multiple rollbacks are allowed)

    or alternatively

    TRANSACTION SET x 1000
    TRANSACTION EXPIRE x 1000
    COMMIT

    but this sucks since there is no way to check the error message.

- Prevent the client to issue SYNC or MONITOR multiple times