WIP create v3 onion service (Fixes #575)

[kradan]

according to config/tor/state this commit has been tested with TorVersion Tor 0.3.3.9 (git-ca1a436fa8e53a32)

In the UI the dialog to add contacts still shows a short id (ricochet:dkska2iuk3byot7g) and I expected it be longer, so maybe this change was not enough to create a v3 onion service yet.

I am waiting here for interested people to test if connections work (ricochet is not always on).

[kradan]

Thanks for the explanation, I expected something like that :) As Ricochet is work in progress (without much progress at the moment though), I updated the original ticket.

[ashleyconnor]

V3 support was recently added to stem so this might be possible now.