LUCENE-5313: leave the default to true for enablePositionIncrements

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/trunk@1537104 13f79535-47bb-0310-9956-ffa450edef68
LUCENE-5296: add DirectDocValuesFormat

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/trunk@1537105 13f79535-47bb-0310-9956-ffa450edef68