Updated openstack/openstack
Project: openstack-dev/devstack  2dba66f328b1b7424b7c8cb4c79f29d26a0c997a

Rework the old logo

* Re-work the old banner logo for the Sphinx docs
* Remove the remaining leftover assets from the old web site

So this is one possibility, I retained the other logo files so we have
options to play with.

Change-Id: Iac15899780072450dc30600a719283c0e2b0c0ae