[vsphere] allow to create a vm with multiple disks.

unitNumber has to be unique.
Merge pull request #1437 from ohadlevy/vsphere-multi-disk

[vsphere] allow to create a vm with multiple disks.
Merge pull request #1436 from westonplatter/master

[docs::aws::storage] reformatted fog/aws/storage/requests delete
adding support for rackspace loadbalancer content caching
Merge pull request #1438 from luizfar/add_content_caching_to_load_balancer

adding support for rackspace loadbalancer content caching
[docs::aws::storage] standardized return format
  for key with values,
    # @return variable [data_type]:
  for values,
    # * variable [data_type] - description of value
[docs::aws::storage] WIP on get requests