Sync oslo imports to the latest version.

Change-Id: I36193d00930e5c82c46841b64650863c811b95a4
Import strutils from oslo, and convert to it.

The only change of behaviour here (according to the former glance
unit tests) is that 'T' now means True not False. I suspect that's
ok.

Change-Id: Icf98f913a3f78a1fe2f38a82a25a071c2da03739
Merge "Sync oslo imports to the latest version."
Merge "Import strutils from oslo, and convert to it."