Fix ceph deployment after upgrade from Cloud 3 (bnc#899909)

proposal["deployment"]["ceph"]["elements"]["ceph-radosgw"] might not always be
a list. So use the already initialized radosgw_nodes variable which is assured
be a (possibly empty) list.

Fixes: https://bugzilla.suse.com/show_bug.cgi?id=899909
Merge pull request #97 from rhafer/bnc899909

Fix ceph deployment after upgarde from Cloud 3
Use region from keystone settings

The keystone barclamp got the possibility to set a custom region
name. This name must be used by other barclamps as well.

related to: https://bugzilla.novell.com/show_bug.cgi?id=896481
Merge pull request #100 from toabctl/custom-region-support

Use region from keystone settings