RDFDatMgr is the preferred way to write an iterators of triples or quads.
Leave SinkTripleOutput and SinkQuadOutput for special cases where more control needed.

git-svn-id: https://svn.apache.org/repos/asf/jena/branches/arq-riot-output@1453448 13f79535-47bb-0310-9956-ffa450edef68