Copy the RHEL6 eventlet workaround from Oslo

Tests in oslo-incubator now need the horrendous hack to workaround an
issue with eventlet on RHEL6. We've moved the patch_tox_venv tool
and redhat-eventlet.patch into oslo-incubator, so add them to
openstack-common.conf.

Change-Id: I1acfec282b64d7582144b155119bedb1741db2f7
Import recent rootwrap features in local rootwrap

Import features developed in oslo-rootwrap during the Grizzly cycle (and
recently in havana) into quantum-rootwrap. This is the first step toward
using the common oslo-rootwrap into Quantum: the goal being to make both
implementations converge, we should avoid making local changes (and push
any required change into oslo-rootwrap instead from now on).

New features include:
- Optional logging (use_syslog)
- Searching for executables in a specified binary path (exec_dirs)
- New path-based PathFilter

Those features required a refactoring in the way executables are matched
and in configuration loading.

Implements bp quantum-rootwrap-new-features

Change-Id: Ia6a2e91c297ade471448dae0964adfd001a46086
Merge "Import recent rootwrap features in local rootwrap"
Avoid extra queries when retrieving routers

fixes bug 1160333

Instead of making N additional sql requests,
use relationship and joined query.

Change-Id: I8f650691916a252bf2a525343bfa0521ff6fbe43
Imported Translations from Transifex

Change-Id: Ia061d1b4580b4363a734b571f25755e50feab119
Merge "Imported Translations from Transifex"
Merge " Copy the RHEL6 eventlet workaround from Oslo"
Don't run metadata proxy when it is not needed

Bug #1159015

Change-Id: I6063e75525a2a727d063bb1745c897ac8c4ba3e8