Error responses from server don't have to contain backend node, only a message.
For example 401 error response looks like:
<error status='401' url='/api/instances'>
  <message>Authentication required</message>
</error>

This patch makes sure that dc-client doesn't fail if 'backend' node is not present.
Deltacloud - record openstack driver realms fixtures for white box unit tests

related to DTACLOUD-477

fix broken build @ https://travis-ci.org/mifo/deltacloud/builds/5039461
Adds 'valid_credentials?' method for digital_ocean driver - DTACLOUD-480

https://issues.apache.org/jira/browse/DTACLOUD-480
Deltacloud - rework 'valid_credentials' - moved to base_driver where possible

Drivers can override this where needed - like e.g. in ec2 driver where just
creating a handle to the aws service (via the appoxy/aws rubygem) isn't enough
to determine that credentials are not valid.
Deltacloud - Tests - adding testpoint for creating an image from a stopped instance - if supported

TrackedAt: http://tracker.deltacloud.org/patch/7f7d5800cbdfe3f288da30cb0050166c3a86b047
Deltacloud - Tests - adding blackbox tests for metrics, firewalls and load balancers

TrackedAt: http://tracker.deltacloud.org/patch/1047c2d5ad628b3e287b05d4e8e152daf46780f0
RHEV-M: avoid failure of GET instance details

  A backtrace was sporadically produced for a
  GET /api/instance/<instance id>

  When one instance is being destroyed during a GET for
  another instance, a backtrace is produced. This is because
  a query for all instances (vms) was being done. The list of
  all instances is gathered, one instance is destroyed, then the
  list contained an invalid instance ID which when queried
  produced
  "Entity not found: id "

  Fixes https://issues.apache.org/jira/browse/DTACLOUD-462

  This change also caused automated VCR test failures which
  has resulted in the re-recording of those tests. The new
  recording has instituted changes to prevent the exposure
  of test bed credentials.
TrackedAt: http://tracker.deltacloud.org/patch/2db40fc62c97d9333a69dd1d94a37e09693f3b72
Deltacloud - Tests - adding blackbox tests for addresses and drivers collections
Deltacloud - Tests - removing reference to 'keys' collection
CIMI - Tests - modifying tests to use *Create
CIMI: Removed debug statements from AddressCollection
Core: Fixed Rabbit namespacing issues with Addresses (DTACLOUD-500)

NOTE: A sinatra-rabbit >= 1.15 is required to make this work and to
fix the bug.
Core: Change prefix for the Sinatra::Rabbit classes

Sinatra::Rabbit for CIMI is now CIMI::Rabbit
Sinatra::Rabbit for Deltacloud is now Deltacloud::CIMI
CIMI: Added VolumeImageCreate model
CIMI: Fixed typo in volume_image column name in database
CIMI: Added VolumeTemplateCreate model
Core: Added possibility to run filter_on with multiple attrs

So instead of writing:

instances = filter_on instances, :id, opts
instances = filter_on instances, :realm_id, opts
instances = filter_on instances, :state, opts

You can now use:

instances = filter_on instances, opts, :id, :realm_id, :state

The backward compatibility with old filter_on included.
Mock: Cleanup in MockDriver code

- Removed obsoleted 'requires' (yaml, base64, etc)
- REALMS moved to 'realms' method
- @@METRICS_NAMES moved to Metric model
- Revamped 'filter_on' methods
- Next 'id' generation moved to separate method

a lot of small changes...
VSphere: Added support for StoragePod

Signed-off-by: Michal fojtik <mfojtik@redhat.com>
TrackedAt: http://tracker.deltacloud.org/patch/a834bcdd870aa2c06e8604081718e7112cdd16a2
Core: Cleanup in deltacloud error HAML views

* Removed all HAML views for handling errors
* Added one HAML view to handle them all

Signed-off-by: Michal fojtik <mfojtik@redhat.com>