Sync middleware audit, base, and notifier from oslo

Pull in middleware modules required to support CADF auditing
reports from Nova.  audit.py requires notify.py, and
notify.py requires base.py.  This is why those 3 files are
being synced, and not others in the
openstack/common/middleware directory from oslo.

The following 3 change IDs included in this sync provide
the main parts of the CADF functions being synced:

Ie67cf4a7 Add audit middleware
Iead2431a Middleware: add notifier
I05ff58   Move wsgi module to deprecated package

The following change IDs additionally included in this sync
provide minor updates to the files that were made after the
main parts of the CADF functions were merged in oslo:

I032616   Changed header from LLC to Foundation based on
          trademark policies
I840c43bf add support to ignore certain request
I2099e1ee Enable hacking H404 test
I04b0cf   middleware: code cleanup

blueprint support-standard-audit-formats

Change-Id: Id15f95a0c354270ba2d5aecb12c4f910905e8c20
Merge "Sync middleware audit, base, and notifier from oslo"