Working on blueprint separate-nova-adminapi. This removes the
admin_only extension attribute and the allow_admin_api flag. The
approach we're going for now is to load all extensions, but
to set an admin-only rule in our policy file for those extensions
that should be limited to just admin users. Now that all of our
admin api code has been moved to extensions, in order to
prevent admin api code from being loaded, simply remove it from
the extension list.
Change-Id: Ic574e06af44922ba764013b769077fc5099fd1a2
e13a36a06c