Cleanup openrc.

- Cleanup openrc, removing the sourcing of functions (which was failing
  for zsh) and remove the *_DEBUG comment since they have been removed
  from the clients.

Change-Id: Ie2e6fb1e770403c4ef3463a850e8151bd312614c
Merge "Cleanup openrc."
Merge branch 'master' of github.com:openstack-dev/devstack