Tor port

Use different tor port than briar itself to avoid problems should users install both briar and the mailbox app on a single device

changed milestone to %Mailbox: Manage app lifecycle

added Sponsor 6 label

changed milestone to %Mailbox: Tor

assigned to @grote

added S: in code review label

mentioned in merge request !26 (merged)

closed with commit 9d5f3e22

mentioned in commit 9d5f3e22

removed S: in code review label

added R: fixed label

added Weight: 1 label

added Mailbox label

added Mailbox app label