SOLR-2245: Improvements to the MailEntityProcessor

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/trunk@1610859 13f79535-47bb-0310-9956-ffa450edef68
SOLR-6179: issue fixed in 4.10 release

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/trunk@1610871 13f79535-47bb-0310-9956-ffa450edef68