the tor_pt_state_location env var now has '/fog' to it to avoid clobbering similar transports launched directly by tor instead of fog. See ticket #12613
removed exempt env list from pt_child_env.
Adds launching multiple chains. Now after finding the needed chains, all the pts needed by the chains are launched first. Then after each pt succeeds, if a chain has all its pts setup, it will launch.
changed remote_host, remote_port into a pair to shorten parameters