Resource providers can be configured using the API or CLI, or they
can also be configured on a per-compute node basis using config
files stored in /etc/nova/provider_config.
This patch adds support for a user defined list of provider config
files to be created on the compute nodes. This can be specified in
user_variables or perhaps more usefully in group_vars/host_vars.
A typical use case would be describing the resources made available
as a result of GPU or other hardware installed in a compute node.
Change-Id: I13d70a1030b1173b1bc051f00323e6fb0781872b
b0fcbce66f