[sugar] Presence Service DBus API notes on wiki

[Dan Williams]

Hi,

I've put up what's currently going to be the presence service's DBus API
here:

http://wiki.laptop.org/go/Presence_Service_DBus_API

Please comment on the API in replies to this message, if you have
comments.  The PresenceService is essentially a thin shim over Avahi
that interprets OLPC/Sugar-specific mDNS service announcements, and
organizes them into shared activities.  It is also the mechanism by
which information about buddies and activities is retrieved, like buddy
icons, /whois-type information, etc.

Dan