SOLR-5681: Fixing CHANGES.txt entry

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/trunk@1597146 13f79535-47bb-0310-9956-ffa450edef68
SOLR-5468: Now in 4.9

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/trunk@1597149 13f79535-47bb-0310-9956-ffa450edef68
Move SOLR-5468 to new features section.

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/trunk@1597156 13f79535-47bb-0310-9956-ffa450edef68
SOLR-5681: Fixing CHANGES.txt entry, moving it into the Optimizations section

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/trunk@1597160 13f79535-47bb-0310-9956-ffa450edef68