merge in 4.8.1 CHANGES.txt
merge in 4.8.1 CHANGES.txt

git-svn-id: 308d55f399f3bd9aa0560a10e81a003040006c48@1595869 13f79535-47bb-0310-9956-ffa450edef68

apache/solr,apache/solr,apache/solr,apache/solr,apache/solr