This patch adds a '-n' option to burnin that takes a comma-separated
list of nodes to perform the burnin on.

Reviewed-by: ultrotter

Allow burnin to use the new drbd8 template (for which case one needs to
disable replacement of disks, burnin does yet support that with drbd8).

The patch also changes do-replace[12] to no-replace[12] as that is what
they actually do.

Reviewed-by: imsnah

Reviewed-by: iustinp

This patch moves the passing of the feedback_fn argument from the
(Exec|Chain)OpCode to the initialization of the Processor instance.

Reviewed-by: imsnah

- Add NEWS file with major changes between versions.
- Bump RPC version number
- No longer serialize in RPC, but just convert to dict

Old Pickle based configuration files can be converted using the cfgupgrade
utility.

Reviewed-by: iustinp, ultrotter

Since we added a new, required parameter to OpCreateInstance, we need to
update burnin to build the correct opcode.

Reviewed-by: schreiberal

Change this to have the exact same parameters as OpQueryInstances.

Also fix burnin which is broken since r146.

Reviewed-by: imsnah

This changes the raising of exceptions from:
  raise Exception, value
to
  raise Exception(value)

as the first form will be removed in python-3000 and the second form is
preferred now.

The changes also involve a few cases of changing from raising standard
exceptions and use our own ones.

The new version also fixes many pylint-generated warnings, especially in
ganeti-noded where I changed many methods to @staticmethod.

There is no functionality changed (barring any bugs).

Reviewed-by: iustinp

Reviewed-by: iustinp

Reason: if left ConfigWriter, nodes don't know to which cluster they belong.
This will bite us later when we'll revisit node join operation.

Cons: we lose the cluster name from the config file, which means a
standalone "cluster.data" is a little bit harder to analyze. But I have
a plan for this which will follow shortly.

Implementing this will also allow us to cleanly fix "gnt-cluster
getmaster".

Reviewed-by: imsnah

Reviewed-by: iustinp

Reviewed-by: iustinp

Also improve the burnin by doing an optional replace-disks.