Make storage schemas configurable

Make storage schemas configurable via "storage_schemas_source" and
"storage_schemas_content" parameters to the module. These are passed
through to the file resource that manages "storage-schemas.conf". In
the event that neither parameter is passed, a default config file will
be installed.
Make storage aggregation configurable

Make storage aggregation configurable via "storage_aggregation_source"
and "storage_aggregation_content" parameters to the module. These are
passed through to the file resource that manages
"storage-aggregation.conf". In the event that neither parameter is
passed, a default config file will be installed.
Merge pull request #3 from gds-operations/configurable-schemas

Make storage schemas configurable