Ship some build with debug logs enabled

There are safety concerns with enabling highly verbose logging on clients, and there are some additional questions we'll need to answer such as whether we disable safe logging (I suspect we should leave it enabled).

The goal is providing a build that allows easier debugging of connectivity problems. Maybe we should provide another bundle, as a troubleshooting build, instead of re-purposing nightly or alpha.

I can see this being useful for all platforms, but this is specifically needed on Android because it isn't possible to customize the torrc (see legacy/trac#29031 (moved)).

In this build imagine setting tor INFO logging, and configuring obfs4proxy with -enableLogging. Somehow we'll need to give easy access to obfs4proxy.log, as well.