TODO for update-cluster
=======================

* dh_installupdatecluster

* A suitable way to handle other packages such as spong, diskless etc. without adding extra fields for every node. Maybe a cluster specific single entry such as <spong> <nfsrootbase> etc.

* notes is not a good way to specify master.

* giving ! as a value for empty fields is not a good idea. It should be 
  really using update-cluster-remove intuitively. -- so a ! will
  cause an error. It breaks mpich. -- and mpich is already fixed, I think.

* How to treat packages which doesn't want cooperate with update-cluster...
  Make update-cluster-xxx packages ? 
