Modified warden to create borrowed cells on-demand and to scrap returned ones.

Change-Id: If32a0da18ff9d4c05645017e5cc7481bbd1ab0cd
diff --git a/utils/warden/bin/clone-node b/utils/warden/bin/clone-node
index 8e60d40..2a3465a 100755
--- a/utils/warden/bin/clone-node
+++ b/utils/warden/bin/clone-node
@@ -4,7 +4,8 @@
 base="$1"
 ip="$2"
 name="$3"
-key="$4"
+shift 3
+key="$@"
 
 sudo lxc-clone -o $base -n $name