LUCENE-4877: additional improvements

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/branches/branch_4x@1465225 13f79535-47bb-0310-9956-ffa450edef68
LUCENE-4877: fix CHANGES entry to be under 4.3

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/branches/branch_4x@1465226 13f79535-47bb-0310-9956-ffa450edef68