[aws:storage] path_style option availability

The path_style option should be available regardless of how an
endpoint override is specified
use original error message if none given
[rackspace|compute] compute_v2 should require fog/rackspace
use Fog::JSON
Add the uncommitted property to the vsphere datastore object
Merge pull request #2399 from davidillsley/master

[aws:storage] path_style option availability
Merge pull request #2097 from burns/fog_json

Update references to MultiJson to Fog::JSON
Merge pull request #2402 from mmatuska/vsphere_datastore_uncommitted

Add uncommitted property to the vsphere datastore object
Merge pull request #2406 from rupakg/hp_examples

[hp] Add documentation and examples for the provider for HP Cloud Services
[hp] Fix links in some documentation pages.