Before a couple weeks ago didn't know Tor had these tests, interesting! Stem
already has tests for spawning tor processes but lacked any with this targeted
focus on its arguments.
I've added our own counterpart for these tests. Many are direct copies but
there were others I improved a little...
https://trac.torproject.org/projects/tor/ticket/14109https://gitweb.torproject.org/stem.git/commit/?id=137d193a026638f066e817e3396cebbbb6ace012
Now that Tor uses Stem to supplement its tests no reason for these to live
separately. Tested by simply building tor and confirming test_cmdline_args.py
is no longer in the generated Makefile.
