SOLR-6680: DefaultSolrHighlighter: avoid CachingTokenFilter when not needed

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/trunk@1642510 13f79535-47bb-0310-9956-ffa450edef68
LUCENE-6031: don't call deprecated TokenSources method (in tests)

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/trunk@1642512 13f79535-47bb-0310-9956-ffa450edef68
add test that files are cleaned up after abort

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/trunk@1642527 13f79535-47bb-0310-9956-ffa450edef68
IW.close() always closes

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/trunk@1642528 13f79535-47bb-0310-9956-ffa450edef68