Merge pull request #45 from dominictarr/fixinvites

Fix invites
pass cb to attachSession
tidy
continue to gossip after failures, but only connect to one instance at a time
Merge branch 'master' into realtime
update pull-inactivity and use graphmitter
emit a remote:authorized when the client has authorized
get friends from friends plugin instead of database
use friends plugin by default, and do not merge permissions if they are undefined
test gossip/replication with friends plugin
friends plugin
remove "easy" plugin
if no options where passed to client, treat it as null
remove debugging