Use command-line args instead of tmpdir

[meejah]

If we have less than ARG_MAX bytes of configuration information, we should be able to launch Tor without creating a temporary file for the torrc configuration file (I believe every Tor option has a corresponding command-line option).

This would satisfy the same use-case that https://trac.torproject.org/projects/tor/ticket/13865 was made for, except without modifying little-t tor.

[meejah]

I have a patch for this in master, but it doesn't try to determine if we're blowing ARG_MAX or not (yet).

Note also that there's an option in tor master to stream torrc data via stdin which would avoid having to check ARG_MAX completely.

[meejah]

This is in master, see #189 for "maybe use stdin".