Add new Node attribute powered

This is just a state of record field and does not necessary
reflect the reality.
Signed-off-by: René Nussbaumer <rn@google.com>
Reviewed-by: Michael Hanselmann <hansmi@google.com>

lib/objects.py

@@ -931,6 +931,7 @@ class Node(TaggableObject):
     "master_capable",
     "vm_capable",
     "ndparams",
+    "powered",
     ] + _TIMESTAMPS + _UUID
 
   def UpgradeConfig(self):
@@ -948,6 +949,9 @@ class Node(TaggableObject):
     if self.ndparams is None:
       self.ndparams = {}
 
+    if self.powered is None:
+      self.powered = True
+
 
 class NodeGroup(ConfigObject):
   """Config object representing a node group."""