Sync latest cfg from oslo-incubator

Main cfg change is:

  e3e5e0e Fixes "is not", "not in" syntax usage
  d156150 Implements import_group

Change-Id: Ie6c0fe0d9d35ef6178a121e4f566207576c8d1e6
fix grammar in NetworkInUse exception

bug 1121555

Change-Id: Ie06ef45d066505b0ec1cd31e73c43ae6985afcde
Merge "Sync latest cfg from oslo-incubator"