New encoding options: encUseCrLf and encIncludeHeader

  * encUseCrLf: Controls the record separator when encoding.  The
    default is True which preserves the current behavior of using \r\n.
    Using False changes the behavior to use \n.

  * encIncludeHeader: Allow control over whether a header row is
    included when encoding records.  The default is True to maintain
    current behavior.  This allows records to be encoded in a streaming
    fashion.  The first batch of encoded records can include a header,
    and remaining batches can omit it.