systemd init file ========= The systemd init file (`contrib/init/bitcoind.service`) has been changed to use `/var/lib/bitcoind` as the data directory instead of `~bitcoin/.bitcoin`. This change makes Bitcoin Core more consistent with other services, and makes the systemd init config more consistent with existing Upstart and OpenRC configs. The configuration, PID, and data directories are now completely managed by systemd, which will take care of their creation, permissions, etc. See [`systemd.exec (5)`](https://www.freedesktop.org/software/systemd/man/systemd.exec.html#RuntimeDirectory=) for more details. When using the provided init files under `contrib/init`, overriding the `datadir` option in `/etc/bitcoin/bitcoin.conf` will have no effect. This is because the command line arguments specified in the init files take precedence over the options specified in `/etc/bitcoin/bitcoin.conf`.