在.net core版的JIEba分词上，做了修改，使其支持net core2.0 和支持Lucene.net接口 ps: 修改了JIEba分词，导致的高亮bug
Analyzer analyzer = new JieBaAnalyzer(TokenizerMode.Search);
Analyzer analyzer = new JieBaAnalyzer(TokenizerMode.Default);
TokenStream = analyzer.GetTokenStream(str,indexReader);