init: Rename systemd units

Use strongswan-starter for the legacy unit and simply strongswan for the
modern one (strongswan-swanctl is configured as alias, which should
cause the installation of symlinks when the service is enabled via
systemctl).

init/systemd-starter/.gitignore

@@ -0,0 +1 @@
+strongswan-starter.service

init/systemd-starter/Makefile.am

@@ -0,0 +1,12 @@
+
+EXTRA_DIST = strongswan-starter.service.in
+CLEANFILES = strongswan-starter.service
+
+systemdsystemunit_DATA = strongswan-starter.service
+
+strongswan-starter.service : strongswan-starter.service.in
+	$(AM_V_GEN) \
+	sed \
+	-e "s:@SBINDIR@:$(sbindir):" \
+	-e "s:@IPSEC_SCRIPT@:$(ipsec_script):" \
+	$(srcdir)/$@.in > $@

init/systemd-starter/strongswan-starter.service.in

@@ -0,0 +1,11 @@
+[Unit]
+Description=strongSwan IPsec IKEv1/IKEv2 daemon using ipsec.conf
+After=syslog.target network-online.target
+
+[Service]
+ExecStart=@SBINDIR@/@IPSEC_SCRIPT@ start --nofork
+StandardOutput=syslog
+Restart=on-abnormal
+
+[Install]
+WantedBy=multi-user.target