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 #268 from toabctl/add-region-support

Use region from keystone settings
[SUSE] Removed unneeded options
[SUSE] Fail to create proposal if there is no keystone