Syncs the following changes from stable/folsom: 769ec65 Don't trap then re-raise ImportError. 8c74b37 Improve exception from importutils.import_class(). 1fb2361 add import_object_ns function Change-Id: Ib6046181ec4712702c30c8a8e938fc9a21b1a594
As a side-effect, openstack.common.setup is getting updated Change-Id: I9f8696ec5c82ef32872e1a974102dcd179eb70f9