SOLR-5159: fix typo in CHANGES entry

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/trunk@1514814 13f79535-47bb-0310-9956-ffa450edef68
make RandomMergePolicy log what MP it is wrapping

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/trunk@1514815 13f79535-47bb-0310-9956-ffa450edef68