Add lab-build snippets and executing them in 'create'. Refactor create/destroy/pristine; also, only virsh destroy VMs if they are 'running'

virshall

@@ -13,8 +13,12 @@ CMD=$1
   exit
 }
 
-echo "*  Executing $CMD against all VMs on lab $LAB"
-ssh root@$HVN "set -x; for node in 0 1 2 3; do VM=vpp${LAB}-\${node}; virsh $CMD \$VM; done"
+VMS=$(ls -1 build/${BUILD}/${HVN}/)
+
+for VM in $VMS; do
+  echo "[$VM] Executing $CMD against VMs on lab $LAB"
+  ssh root@$HVN "virsh $CMD $VM"
+done
 
 [ "$CMD" = "start" ] && {
   echo "*  Committing OVS config"