sync oslo bits

update gettextutils.py, strutils.py, install_venv_common.py
remove iniparsers.py

oslo-incubator commit 1223cf

Change-Id: I23923d580f57ab6c12622f10d9f278c44c863feb
Updated from global requirements

Change-Id: Ia54da66d13b2667375a8a85c97ced25fd97b6b25
Merge "sync oslo bits"