Comment 3 for bug 917593

Nova recently faced a similar problem. It was solved by actually making
the devstack configuration of nova simpler. Before, nova had a sample
paste config, and devstack had a nova paste config that was nearly a
duplicate of that. By changing devstack to just use the sample paste
config from nova (adding a few items to it when it copied it into
place), some of the configuration of nova is kept in the nova repository
so that it can be handled by a single change. It also makes devstack
slightly simpler and reduces duplication of configuration files. Here
is the change that implemented that in devstack:

https://review.openstack.org/#change,2978

From a quick look at the changes you mentioned, I think a similar
approach may work here. Otherwise, the changes need to merge in
sequence, so making devstack handle both forms (perhaps temporarily) is
the second best way to go.