Finally, it's there : we can now black-or-white list TOR relays based on location, from the main interface.
It's a little difficult to explain, so here is the demonstration video (I apologize for the video quality, filming this tiny screen is not so easy) :

Basically, it allows to force or block relays, based on their location (246 countries....). It was a really important feature from start, but some work had to be done to allow this possibility.

One could notice the menu is not so nice yet, and this feature still needs a "complete reset" and a easy to read list of white-or-black listed node locations : it may be a little difficult to know the current settings. But hey, it's not a big deal, the hard part is done already.

Now, I want to be able to determine the exact circuit TOR is using, maybe show it on a map. I already have a few ideas about how to do it, even some code snipplets ready, but it is another story.

Now, I could easily watch Doctor Who's new season live episodes on BBC from France... :-)