Added 'raet_join_fresh' to opts
If TRUE when RoadStack starts up it blows away persisted remotes
If FALSE then it uses its persited remotes

On a minion this means that if TRUE it will use the opt 'master' to determine which masters
to join to Otherwise it will join to preexiting masters it joined to last time it ran.

On a master this means that if TRUE it forgets all the minions and they must rejoin
If FALSE it will start using presence on all preexisting minions
Change raet_join_fresh to raet_clear_remotes
as more descriptive of what really happens