Tor Browser should NEWNYM on launch, if TOR_SKIP_LAUCH is set.

I'm open to being told this is dumb, and this only applies to people using a system wide Tor instance.

My view on the matter is, Tor Browser's behavior with regards to circuit use should be closer between using Browser managed Tor and system Tor. If the user is proving a Tor instance, restarting the browser should cause outbound connections to be made on fresh circuits, rather than those built/associated with the previous session.