SOLR-6680: DefaultSolrHighlighter: avoid CachingTokenFilter when not needed

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/branches/branch_5x@1642511 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/branches/branch_5x@1642513 13f79535-47bb-0310-9956-ffa450edef68