This patch removes the majority (everything except for the user
image) of image building from devtest_overcloud.sh and provides
a hook to use devtest_overcloud_images.sh or a new build-images
script.
The motivation for this split out was to decrease the complexity
of the devtest_overcloud.sh script while also increasing
the flexability of our devtest_overcloud image building process.
For example:
Some configuration tools (tripleo-image-elements) require that each
role have very specific sets of elements to enable or disable
functionality.
Other configuration tools (puppet) allow image to be built in a variety
of ways. You could use a very minimal base image and install packages
at deployment time. Or alternately you could use images where packages
get pre-installed based on the role. Or you could use just one
image for everything (all the OpenStack packages get pre-installed).
This is an initial step towards making devtest_overcloud.sh
more flexible and configurable with regards to image building.
Change-Id: Idccd180813498401898f10b502106585b1f18eb3
14c94f85de