This adds a module for getting information on one or more
object storage containers from OpenStack.
The following options are supported:
* name - Get details for a single container by name.
When this parameter is defined a single container is returned,
with extra metadata available (with the same keys and value
as in the existing object_container module).
* prefix - Search for and return a list of containers by prefix.
When searching for containers, only a subset of metadata values
are available.
When no options are specified, all containers in the project
are returned, with the same metadata available as when the
prefix option is used.
Change-Id: I8ba434a86050f72d8ce85c9e98731f6ef552fc79
5494d153b1