Use consistent naming of components

Rename "pvcd" to "pvcnoded", and "pvc-api" to "pvcapid" so names for the
daemons are fully consistent. Update the names of the configuration
files as well to match this new formatting.

References #79

node-daemon/pvc-flush.service

@@ -2,8 +2,8 @@
 
 [Unit]
 Description = Parallel Virtual Cluster autoflush daemon
-After = pvcd.service
-PartOf = pvcd.target
+After = pvcnoded.service
+PartOf = pvc.target
 
 [Service]
 Type = oneshot
@@ -15,4 +15,4 @@ ExecStop = /usr/bin/pvc -c local node flush --wait
 ExecStopPost = /bin/sleep 30
 
 [Install]
-WantedBy = pvcd.target
+WantedBy = pvc.target