This doesn't need any interacion of the user at startup, unlike
retroshare-nogui which requires the user to login on the shell this doesn't
even need a TTY.
At startup this just parse command line, read the PGP keyring, look for
available locations, and start listening for JSON API requests.
Another difference with retroshare-nogui is that this is capable to
generate/import PGP identities, generate locations, and in general anything
possible through the RetroShare API.
retroshare-service is suitable also to run it as a system service, even
in very constrained systems such as Android ot a Docker container.
retroshare-service drop support for libresapi so only the new JSON API
is exposed, it will completely obsolete retroshare-android-service once
retroshare-qml-app is ported to the new JSON API.
