systemd: run as Type=simple

Problem: powermand runs as a Type=forking systemd service,
but Type=simple is recommended by systemd.service(5).

Switch to Type=simple (the default).

Drop the tmpfiles.d configuration which was for managing
/run/powerman on systemd < v233 (now ancient).  Powerman doesn't
need the rundir anyway when not running in daemon mode, since all
it does is store a pidfile there.

Fixes chaos#13

configure.ac

@@ -130,7 +130,6 @@ AC_CONFIG_FILES( \
   etc/Makefile \
   etc/libpowerman.pc \
   etc/powerman.service \
-  etc/tmpfiles.d/powerman.conf \
   heartbeat/Makefile \
   man/Makefile \
   man/powerman.1 \

etc/Makefile.am

@@ -1,7 +1,5 @@
 if HAVE_SYSTEMD
 systemdsystemunit_DATA = powerman.service
-systemdtmpdir_ddir = ${prefix}/lib/tmpfiles.d
-systemdtmpdir_d_DATA = tmpfiles.d/powerman.conf
 endif
 
 if WITH_PKG_CONFIG

etc/powerman.service.in

@@ -4,12 +4,10 @@ After=syslog.target network.target
 
 [Service]
 Environment=SHELL=/bin/sh
-Type=forking
 PrivateTmp=yes
 User=@RUN_AS_USER@
 Group=@RUN_AS_GROUP@
-ExecStart=@X_SBINDIR@/powermand
-PIDFile=@X_RUNSTATEDIR@/powerman/powermand.pid
+ExecStart=@X_SBINDIR@/powermand -f
 
 [Install]
 WantedBy=multi-user.target