Sync with latest version of openstack.common.importutils
Sync with latest version of openstack.common.importutils

Changes since last sync:

 - Improve exception from importutils.import_class().
 - Merge "add import_object_ns function"
 - Update common code to support pep 1.3. bug 1014216
 - add import_object_ns function

Change-Id: Ibaa60f50af255ec77a3f0c93213f8a9f446eeb0d

vuntz/glance,rickerc/glance_audit,dims/glance,klmitch/glance,takeshineshiro/glance,ntt-sic/glance,paramite/glance,akash1808/glance,JioCloud/glance,SUSE-Cloud/glance,scripnichenko/glance,kfwang/Glance-OVA-OVF,rickerc/glance_audit,citrix-openstack-build/glance,rajalokan/glance,sigmavirus24/glance,SUSE-Cloud/glance,citrix-openstack-build/glance,scripnichenko/glance,dims/glance,saeki-masaki/glance,darren-wang/gl,openstack/glance,redhat-openstack/glance,kfwang/Glance-OVA-OVF,cloudbau/glance,jumpstarter-io/glance,wkoathp/glance,tanglei528/glance,sigmavirus24/glance,akash1808/glance,ozamiatin/glance,klmitch/glance,wkoathp/glance,ozamiatin/glance,takeshineshiro/glance,darren-wang/gl,jumpstarter-io/glance,stevelle/glance,paramite/glance,cloudbau/glance,JioCloud/glance,saeki-masaki/glance,ntt-sic/glance,redhat-openstack/glance,tanglei528/glance,openstack/glance,rajalokan/glance,stevelle/glance,openstack/glance,vuntz/glance