roster could be public
rename roster to helper, since roster could be a query...
i guess it didn't make sense to remember roster helper...

since it's not only a help, but would also send a query!
subscribe without roster
so we don't really need a roster helper...
properly consume the message
then we could call start to restart
add .gitignore to gemspec
shorter inspect
make chaining easier
so we need to remember the helper after all...

since the callbacks are still retained, and they would be
eating up all the iq!
make it clear that it's jid
so we have sync and async mode for accessing roster
version bump
added CHANGES.md