Update elements to use os-svc-install -i.

Globally updates all the elements so we explicitly set the
virtualenv install directory with the os-svc-install -i option.

A step towards supporting both isolated and global venvs
for OpenStack elements installed from git source.

Change-Id: I2ce9a383adc36457654b155f0c14f399a2992323
Wire in OPENSTACK_VENV_DIR default if set

Updates the various environment.d elements which setup
{SERVICENAME}_VENV_DIR so that if OPENSTACK_VENV_DIR is set
it is used as a default. The in-element service name variable
if set will still override any OPENSTACK_VENV_DIR so that
per element exclusions can be made for any global venv.

Change-Id: Iba9d957f3e89c22bad9e32fa63095b7ad50fe503
Fixup Ironic support.

This patch adds ironic settings to config.json suitable for
bootstrapping an Ironic seed. A missing template for providing an ssh
key for current Ironic SSH power driver use is added.

Nova.conf had an extraneous no-op firewall driver option (we always
use the no-op driver because either neutron does it, or its baremetal).

There were post-install scripts for install operations, so fix them
up. Finally, the script to make a local SSH key is unneeded because
we supply credentials from outside.

Co-Authored-By: Chris Krelle <nobodycam@gmail.com>
Change-Id: Ie1263dde6786c40280032deae1c072cd6e5aa194
Merge "Fixup Ironic support."
Merge "Update elements to use os-svc-install -i."
Merge "Wire in OPENSTACK_VENV_DIR default if set"