docs: move CHANGES entries from 4.0 to 3.1
docs: move CHANGES entries from 4.0 to 3.1

git-svn-id: 308d55f399f3bd9aa0560a10e81a003040006c48@1072181 13f79535-47bb-0310-9956-ffa450edef68

PATRIC3/p3_solr,PATRIC3/p3_solr,PATRIC3/p3_solr,PATRIC3/p3_solr,PATRIC3/p3_solr,PATRIC3/p3_solr,PATRIC3/p3_solr