LUCENE-5097: Analyzer now has an additional tokenStream(String fieldName, String text) method, so wrapping by StringReader for common use is no longer needed. This method uses an internal reuseable reader, which was previously only used by the Field class.

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/trunk@1500862 13f79535-47bb-0310-9956-ffa450edef68