Support openvpn status file
    
    OpenVPN uses a status file that it constantly writes to (rather than append, as
    used for the other log files). As this is less of a log file and more of a state
    file, create a separate type and allow openvpn_t manage rights on it.
    
    Signed-off-by: Sven Vermeulen <sven.vermeulen@siphos.be>