LUCENE-4733: merge Lucene42 codec from lucene-4547 branch

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/trunk@1441571 13f79535-47bb-0310-9956-ffa450edef68
mark r1441571 as merged

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/branches/lucene4547@1441573 13f79535-47bb-0310-9956-ffa450edef68