Bugfix: DIOs with infinite ranks should not be ignored as they are used by RPL as a signal by nodes that have lost their routes. Instead of ignoring them, we should send out our latest information to let the node with infinite rank find their way into the network again.
Minor code style fix
Merge pull request #301 from adamdunkels/hotfix-rpl-max-dio

RPL bugfix: don't ignore infinite rank DIOs