Sync unhandled exception logging change from Oslo

Copying changes from 1 Oslo commit: Ibf00173a07510b2ec0c81a29624004f17810a4e4
This is related to the bug fix for adding error type to unhandled
exception log message.

Change-Id: Ie8af57a148753121f79136af928feb0edaea228b
Closes-Bug: #1265561
Merge "Sync unhandled exception logging change from Oslo"
Merge commit 'refs/changes/61/58861/12' of git://gold.eng.hq.xensource.com/git/github/openstack/nova into tmpbranch
Merge commit 'refs/changes/53/60253/8' of git://gold.eng.hq.xensource.com/git/github/openstack/nova into tmpbranch

Conflicts:
	nova/virt/xenapi/vm_utils.py
Merge commit 'refs/changes/08/60808/6' of git://gold.eng.hq.xensource.com/git/github/openstack/nova into tmpbranch
Merge commit 'refs/changes/97/66597/4' of git://gold.eng.hq.xensource.com/git/github/openstack/nova into tmpbranch
Merge commit 'refs/changes/79/69879/3' of git://gold.eng.hq.xensource.com/git/github/openstack/nova into tmpbranch