reset prereqs status on clean.sh

when running a clean, we should really reset the prereq status as
well, as this should start us back from zeroish.

Change-Id: I5fae151ab13bcf7fb82feb1e91eed19e0215dc59
Fix missing libffi-devel for python-glanceclient

python-glanceclient is failing to install on rhel6 with a dependency
chain from pip as

  cryptography>=0.2.1 (from pyOpenSSL>=0.11->python-glanceclient==0.12.0.56.gb8a850c)

cryptography requires libffi-devel to build.  I'm not sure what
changed, but remove it from "testonly" so it is always installed.

However, RHEL6 includes this in the optional repo, so we enable this
repo in the fixup script.

Change-Id: I9da0e91b75f41578861ee9685b8c7e91dd12dae7
Create stack_domain_admin user

Create an additional service user for Heat, which is a domain admin
for the stack_user_domain - this is necessary since the normal service
user cannot manage the projects/users in the stack_user_domain when
keystone is configured to use the v3cloudsample policy (such as in
gate integration tests).

Change-Id: If59c11a74145b9bd02f78a7e0882afe1b0a72e40
remove sysstat & pidstat

dstat is far cleaner for getting results out of the environment,
and covers the bulk of our use cases for sysstat and pidstat with
a much better ui.

devstack is allowed to be opinionated, so become opinionated here.

Change-Id: I21ec96339dcd704098512fdafd896738f352962d
Merge "Fix missing libffi-devel for python-glanceclient"
Merge "reset prereqs status on clean.sh"
Merge "remove sysstat & pidstat"
Merge "Create stack_domain_admin user"