LUCENE-2858: Move the ReaderContexts out of their enclosing classes and make top-level classes. Makes import statements not so verbose and its much easier to understand. Prevent subclassing of IndexReader and IndexReaderContext directly.
lucene/dev/branches/lucene2858/lucene/contrib/highlighter/src/java/org/apache/lucene/search/highlight/WeightedSpanTermExtractor.java