Sync gettextutils from oslo

Some Messages, such as those created from Invalid exceptions, use a
Message within a Message, and we were only translating the base Message
but not the Message substitution within.

Also adds test case for cinder case.

Fixes bug: #1221808

Change-Id: Ic3119df23a090cfaa160c1461e955f0af55fe1cf
Merge "Sync gettextutils from oslo"