Added to fix RHEL specific issues with config files

When installing on RHEL or using the RDO packages REDHAT installs
configuration files for specific services into directories under /usr/share
these additional configuration files are in direct conflict with the configs
that are in /etc/

To fix this issue we are truncating the file ceilometer-dist.conf and 
overloading the file in ceilometer.conf with the values that were in the 
dist.conf file. In this case we are simply setting the control_exchange and
which RPC driver to use.

(cherry picked from commit 95dee575ac2230870d7ea63b6ac98c4ffde7b146)

See rcbops/chef-cookbooks#799