Final Orfox update

I'm debating how we should do this. Ideally, we want to migrate all Orfox users to TBA. In this ideal world, I would propose creating a very simple app as a replacement for Orfox where this new app simply says something like "Orfox is now Tor Browser for Android! Please install it from ". We can detect if the device has the Play store or F-droid installed and give the user one of the links. We can also offer a way to migrate the users bookmarks from Orfox to TBA.

The real world is more complicated than the ideal world. I worry about releasing an update of Orfox that completely replaces its current functionality with a simple-migration-tool. However, realistically, no one should be using Firefox 52esr now, so moving users away from that is important. With that being said, people should have a choice.

One problem is we can't easily release a new version of Orfox (based on 52esr) because Google Play won't accept it due to stricter requirements that went into effect last October. Therefore, we are in a not so great situation with this.