Introduce dontaudit interfaces for leaked fd and unix stream sockets
    
    The fail2ban application leaks file descriptors and unix stream sockets when it
    invokes sendmail, so introduce the necessary dontaudit interfaces which will be
    used in a later patch against the mta and postfix policies.
    
    Signed-off-by: Sven Vermeulen <sven.vermeulen@siphos.be>