LUCENE-5897, LUCENE-5400: JFlex-based tokenizers StandardTokenizer and UAX29URLEmailTokenizer tokenize extremely slowly over long sequences of text partially matching certain grammar rules.  The scanner default buffer size was reduced, and scanner buffer growth was disabled, resulting in much, much faster tokenization for these text sequences. (merged trunk r1619730)

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/branches/branch_4x@1619773 13f79535-47bb-0310-9956-ffa450edef68