Add configuration to the omnibus builds

Some of the configurations files that may be needed by the OpenStack
services are not always available from the various config management
solutions, therefore, pull in any configs from the repo itself.
Add numpy to the standard build

numpy is a requirement for various projects, so add it to the common
site-packages.
Make sure we are including libffi

Looks like libffi was missing from the list of openstack-common
dependencies.
Adding a missing comma

Sadly, I missed this comma in the last commit.
Move ffi includes to the to include dir

Not sure why libffi wants to install its heaaders to the lib directory
but we really prefer them to be in the standard include directory. Move
them there.