XS should have a managed roster to allow subsets of XOs to collaborate

[mchua]

(Brought up at the XS/tech support meeting at 1cc on 12 November 2008, listing here for documentation purposes.)

A managed roster to allow XOs to connect/collaborate in groups. When this works, an XO won't see all 3000 XOs in its school in Neighborhood, it'll see a smaller number of the ones that "make sense" for it to see. (It is not yet clear what the definition of "makes sense" is in this context.)

[mstone-xmlrpc]

Pushing out to 9.1.0, per edmcnierney's request.

[martin.langhoff]

This is fixed in XS-0.6