Partial MOBIKE implementation
Initial support of [source:trunk/doc/standards/rfc4555.txt RFC4555].
For the first release with MOBIKE, we target simple roaming of the initiator. This includes MOBIKE support indication, address list exchange and simple address update. The initiator should detect changes in his interface/address list and roam to another address pair if the current gets unusable. This includes romaing from an to NATed situations.