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

(cherry picked from commit 5c259254fd5448d3074feaf9ba730005bf24d7ec)
Merge pull request #99 from dirkmueller/release/stoney/master

Use region from keystone settings