Lazy Network Neighborhood updates

[Mikus Grinbergs]

> We already readjust the network neighborhood layout on the fly when we
> switch view. It's funny to see the access points slide around  :-) 

Haven't bothered to keep track of the appearance/disappearance of XO and
AP icons in Neighborhood View - it's hard to figure out whether their
presence on screen is determined by View updating or by radio reception.

But something that needs attention is the handling of "invitation icons"
in Neighborhood view.  I would like such an icon to mean "there exists
RIGHT NOW someone else with whom I can collaborate".  Instead, these
icons seem to persist long after all invitors/invitees are gone.

Thanks,  mikus