Make Decentralized SSL Observatory / Tor interoperability sane again
The Decentralized SSL Observatory has an option to use Tor (via Torbutton) for strongly anonymised submissions of X.509 certs. Unfortunately, when Torbutton switched to being "always on", users lost the ability to use the Observatory all the time with Tor acting as the background submission method.
So what we should do is pull the components out of Torbutton that detect a local Tor instance, see if the regular and Tor Browser Bundle Tor proxy ports are open, ping check.torproject.org over those, and determine whether Tor is locally available that way.
I will also replace "Torbutton" with "Tor" in the UI when that patch is ready.
(This is blocking 3.0 stable, because all of the advice in the UI about Tor and the Observatory is currently weird/wrong, and lots more people will see that advice when 3.0 stable ships)