Adds openstack_region parameter to OpenStack Identity Service
Improved OpenNebula support

This patch improves Fog's OpenNebula support in a number of ways:
Better NIC support in VM templates
Better ability to tune number of CPUs and memory
Ability to add/remove entries from a VM template's context section
Ability to add/remove entries from a VM template's user variables
Improved filtering for templates and NICs
Improved OpenNebula support

This patch improves Fog's OpenNebula support in a number of ways:
Better NIC support in VM templates
Better ability to tune number of CPUs and memory
Ability to add/remove entries from a VM template's context section
Ability to add/remove entries from a VM template's user variables
Improved filtering for templates and NICs
[vSphere] Support clusters that are located below folders
[vSphere] Support non-clusters setup
Updating authentication functions to prevent sending expired token.
Clusters lists tests
Adding Tests and Mocks

Adding several test cases for flavors and updating network tests to
support new attributes.
Merge branch 'opennebula' of github.com:blackberry/fog into opennebula

Conflicts:
	fog.gemspec
	lib/fog/opennebula/models/compute/networks.rb
	lib/fog/opennebula/requests/compute/list_networks.rb
Merge remote-tracking branch 'upstream/master' into opennebula

Conflicts:
	fog.gemspec
Fixing merge conflict
Removing version dependency
Handle Docker authentication errors

Fog was not handling at all the error returned by docker-api. This
commit fixes that and raises an AuthenticationError that can be caught
by Fog clients.

There was a bug in the errors code for container_action that this PR
fixes too.
add block_device_mapping_v2
fixup! example block_device_mapping_v2
clarify getting started README

closes #2148
Merge pull request #3255 from blackberry/opennebula

Improved OpenNebula support
Merge pull request #3268 from eLobato/fix_docker_errors

Handle Docker authentication errors
Merge pull request #3266 from amhuber/master

Updating authentication functions to prevent sending expired token.
Merge pull request #3262 from shlomizadok/master

[vSphere] Support clusters that are located below folders