Fix broken logging imports.

This fixes all of the files incorrectly importing logging directly
and removes the workaround in hacking.py that was due to improper
from nova.openstack.common.log import logging statements.

Change-Id: Icfc25dc148c4a7b5fa7f6a7b609cd6c3d94efee1
Sync latest install_venv_common.py

Syncs:

  c78b2ab Avoid using cfg in install_venv_common

So that people don't need oslo-config installed to run install_venv

Change-Id: I05b69f043b276d5e6cd2df5d90bc679df6373383
Merge "Fix broken logging imports."
Merge "Sync latest install_venv_common.py"
Merge remote-tracking branch 'm_src_repo/master' into build-temp