Add salt configuration for openvpn for use on Azure.

Sets up openvpn for container to container communication. Azure
deploy scripts create certs used for openvpn conneciton. Salt
installs and configures openvpn.
Remove commented lines from openvpn config files.
Merge pull request #1027 from MSOpenTech/azure-scripts

Add salt configuration for openvpn for use on Azure.