Add --with-gpp-default-behavior configure switch.
    
    Only LOCAL_ONLY,LOCAL_FIRST and REMOTE_FIRST allowed.
    REMOTE_ONLY is recognized but configure aborts as long as it is not supported.
    
    Signed-off-by: Günther Deschner <gdeschner@redhat.com>
    Reviewed-by: Simo Sorce <simo@redhat.com>