[aws|storage] Add Fog::Storage::AWS#delete_multiple_objects
[aws|storage] Add mock for Fog::Storage::AWS#delete_multiple_objects
[aws|storage] Little improvements to delete_multiple_objects tests
[aws|storage] Add Fog::Storage::AWS#delete_multiple_objects
[aws|storage] Add mock for Fog::Storage::AWS#delete_multiple_objects
[aws|storage] Little improvements to delete_multiple_objects tests
Added versioned delete_multiple_objects support

Added the VersionId support in the delete_multiple_objects method.
Assume that all object versions are specified in the versionId hash.
The hash maps an object name to an array of versions. If a multiple
versions are to be deleted, the caller must insert the object
multiple times into the object_names array and insert all the versions
into the array associated with that object_name.
[core] Splits Fog::VERSION into own file

Now available within "fog/core"

Just reverted a change where depending on Fog::VERSION for the
User-Agent made a dependency on requiring "lib/fog" which also requires
all providers and services.

That is highly undesirable from a modular perspective!
[core] Adds fog User-Agent header

As discussed in #1026 this adds a User Agent HTTP header to help identify
the version of fog is accessing APIs.

This revised version fixes issue #1310
[core] Updates Rakefile to use Fog::VERSION

No longer need to read in `lib/fog` to access the VERSION mostly because
we are already requiring it anyway in the Rakefile!

The #version method just repeats Fog::VERSION

`rake -T` works and changelog generates
Merge pull request #1311 from fog/1310_version_agent_header

Moves Fog::VERSION to fog/core, Adds User-Agent header
Sync with latest OpenStack flavors extensions.

Updates the OpenStack flavors model/request/and tests so
that they support the latest upstream flavor extensions in
Nova Folsom.

Also updated the Fog tests so they pass with both mocks and reals
(tested against OpenStack deployed on Fedora).
Merge pull request #1312 from dprince/flavor_test_updates

Sync with latest OpenStack flavors extensions.
[Brightbox] Refactors credential code in Compute
OpenStack floating_ip (aka address) test fixes

Updates to the OpenStack address tests so that:

 * The tests cleanup after themselves when executed in Real mode.
   Previously running these tests in Real mode would leak servers
   and floating IPs.

 * DRY things up a bit.

 * Make use of the floating IP we create in subsequent tests. Previously
   the last floating IP in the full list was used. This could be
   problematic in some cases.

--

Also adds a missing Mock class for the release_address request so
that FOG_MOCK tests continue to pass.
fixes issue#1313 ~ Creating user via `Aws.iam.users` ignores `:path`
[Brightbox] Extracts authentication connection

Moving the URL for the authentication endpoint up to the instance level
rather than hiding the logic in the method. Eliminate the need for
options on a private method.

Also cleaned up references to credentials in same method.
[Brightbox] Refactors how tokens are requested

Extracting existing strategies out of Compute
[Brightbox] Moves tokens to CredentialSet
[Brightbox] Extracts parts of request out of compute

* Adds simple helper to get token for service
* Low level request #request_access_token is provided to request
  access tokens