Generate a config file for each client generated

 * Add an openvpn_server variable
 * Move ${openvpn_client}.{key,csr,crt} to
   ${openvpn_client}/client.{key,csr,crt}
 * Generate ${openvpn_client}/${openvpn_server}.ovpn config file
 * Copy over a self contained directory of file per client that can be
   imported by networkmanager in ubuntu or run directly with `sudo
   openvpn ${openvpn_server}.ovpn
Merge branch 'master' of https://github.com/perurbis/sovereign