Merge pull request #3 from Oryon/master

Improve user-friendlyness by answering shorter dns requests
Disabled dot target for now (OS X 10.9 broke my macports, gnn).
Fixed? elsa_pa_stress to work with current code.
Some documentation updating + fixed is_only_visible_router to be bit less suspicious looking.
Added appropriate lsa_changed notifications when neighbor relations change.
Added rather heavy caching of ac_tlv decode results (not elegant, but seems to address major pain point).
Implemented also more clever prefix info handling - now it's gathered in one place, and consumed in two (in loops too).
Merge branch 'vancouver' of https://github.com/fingon/hnet-core into vancouver