Merge branch 'default-client-ports'.
This unifies endpoints used by the client in the different current scenarios: standalone binary, Docker container, Android library. Now the default HTTP proxy endpoint is `127.0.0.1:8077`, and the default front-end endpoint is `127.0.0.1.:8078`, with both enabled by default. The reason for `127.0.0.1` and not something less prone to clashes like `127.7.2.1` (as we do in the injector) is that the client is expected to run on many platforms (while we can assume GNU/Linux for the injector), and not all of them support binding to addresses in `127.0.0.0/8` other than `127.0.0.1` (e.g. macOS and other BSD-based systems). Thus it becomes more reasonable to choose a less crowded port (8077 and the following one in this case). Documentation and other references in code and other files have been updated as well.