Drop unused cookbook_file for nova-common

It was never run, so it's not really needed.
Merge pull request #299 from vuntz/no-nova-common

Drop unused cookbook_file for nova-common
Drop executable bits on files
Update migration script
Merge pull request #300 from mjura/release/roxy/vmware-support

Update migration script
Merge pull request #301 from vuntz/no+x

Drop executable bits on files
Run chef-client for all compute nodes in the same batch

The element_order attribute specifies how batches are going to be run
when applying the roles. Until now, we put each compute role in its own
batch; but that's not required as a node can only have one compute role,
and we have no issue running chef-client on all the compute nodes in
parallel.

Very concretely, this means that the xen role will now be applied at the
same time as the kvm role, while before, we were waiting for the kvm
role to be applied before applying the xen one.

The issue with the previous approach is that the periodic chef-client on
the xen node can be triggered while the other roles are being applied,
and it will possibly reboot the node -- making the node non-reachable
from apply_role when it's its turn to have a chef-client role.

While this change won't 100% fix the above issue, it will greatly reduce
the risk. And it's a change that makes sense anyway.

This helps a bit with https://bugzilla.novell.com/show_bug.cgi?id=859865
Merge pull request #302 from vuntz/compute-in-one-batch

Run chef-client for all compute nodes in the same batch
Add compute hosts to their availability zone

There's a new crowbar-nova-set-availability-zone utility that will be
run on the controller node to configure the availability zone of compute
nodes. It will only do so when the compute nodes are known to the
controller nodes, which might happen after the first chef-client run;
but 15 minutes later, everything will go fine.
Do not move to default AZ nodes that are in non-crowbar AZ

If the cloud admin manually creates AZ, then we don't want crowbar to
override that. So nodes that have no configured AZ will stay in a
non-crowbar AZ if they're configured so.
Add "-AZ" to crowbar prefix for host aggregate names

Crowbar might create non-AZ related host aggregates in the future...
Merge pull request #293 from vuntz/az

Add compute hosts to their availability zone
Restore virtual guests by default on host reboot

Helps at least with some "availability" accross reboots..
Use standardized string for Logging option