Added '-o wmark' option to rdkafka_example to get partition offset watermarks
Added '-o wmark' option to rdkafka_example to get partition offset watermarks

klonikar/librdkafka,orthrus/librdkafka,klonikar/librdkafka,senior7515/librdkafka,orthrus/librdkafka,klonikar/librdkafka,orthrus/librdkafka,janmejay/librdkafka,senior7515/librdkafka,janmejay/librdkafka,janmejay/librdkafka,janmejay/librdkafka,senior7515/librdkafka,klonikar/librdkafka,senior7515/librdkafka,orthrus/librdkafka