deploy: Add missing cyclades options for ext

The ext disk template needs some extra parameters that are defined
in cyclades settings. Add those missing settings.

Additionally remove any hardcoded references to /srv/ganeti since this
is configurable.

Change mails found in cyclades.conf to examples (e.g
user@synnefo.org).

Add shared-filer ext provider too (by installing ExtStorage
component too).

Signed-off-by: Dimitris Aragiorgis <dimara@grnet.gr>
deploy: Support run command

..to kinda simulate pdsh. Specifically:

  snf-deploy run --setup synnefo --cmd "apt-get update" -vvv

or:

  snf-deploy run --target-nodes node1,node2 --cmd "apt-get update"

Signed-off-by: Dimitris Aragiorgis <dimara@grnet.gr>
cyclades: Fix ext storage support

Pass origin disk parameter and img_id None only if provider
is included in GANETI_CLONE_PROVIDER list.

Signed-off-by: Dimitris Aragiorgis <dimara@grnet.gr>
pithos: Fix wrong quotas when moving objects

Quotas were not accounted correctly when moving an object or a folder to a
path that another object already exists.

This commit fixes this issue.

In addition to this, the backend during move operations used to issue the quota
change for each separate operation (copy & delete) and for each affected object
(in the case of bulk move operations).

This commit introduces the following enhancement:

In case of a move operation to the same account or to the same project computes
the whole quota change and contacts the quota holder component only once
(at the end of the whole procedure) for the specific account/project.

However, we do not perform the same for copy operations because we want to
catch quickly failures due to quota restrictions.

Fixes #2
pithos: Reorganize backend testing code.

Break backend testing code into several modules and extent the tests to
challenge also the sqlite backend module.
pithos: Provide tests for the quota commissions