SOLR-6833: clean should remove example directories created by running bin/solr -e foo
SOLR-6833: clean should remove example directories created by running bin/solr -e foo

git-svn-id: 308d55f399f3bd9aa0560a10e81a003040006c48@1645737 13f79535-47bb-0310-9956-ffa450edef68

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