Log process ID + process name

[JeremyRand]

We should consider logging the PID (os.Getpid()) and process name (os.Args[0] and os.Executable()). This would help for debugging things such as Chromium-specific "built-in trust anchor" disabling, and per-process Tor stream isolation. Maybe also the thread ID (syscall.Gettid()).

[JeremyRand]

This would also help us debug whether Firefox's Fission feature isolates PKCS#11 modules. If it does, that would give us per-domain Tor stream isolation. Unfortunately, Fission does not yet key the isolation by first-party domain, so this is not sufficient for anonymity. (Also Tor Browser doesn't enable Fission by default AFAIK.)