Sync latest gettextutils from oslo-incubator

The translation message improvements are the main addition of
interested because they are required to support lazy message
evaluation.

Commits included:

  afdbc0ac5 Fix E501 in individual openstack projects
  6b2d15fe6 Merge "Add support for locales missing from babel"
  9d529dd32 Make Message keep string interpolation args
  ec6d90019 Add support for locales missing from babel
  221c37d44 Allow the Message class to have non-English default locales
  0e1af5bed Implementation of translation log handler
  f5686b19d Merge "Translation Message improvements"
  8b2b0b743 Use hacking import_exceptions for gettextutils._
  2cfc1a78d Translation Message improvements
  45658e2f3 Fix violations of H302:import only modules

Note that the following touched other files, but the changes were
independent and did not require inclusion of additional files:

  8b2b0b743 Use hacking import_exceptions for gettextutils._
  45658e2f3 Fix violations of H302:import only modules

Partially implements blueprint i18n-messages

Change-Id: I3ac748d0cf73d841330675e8eb02a5bb1bbc9f1e
Merge "Sync latest gettextutils from oslo-incubator"