Cull the amount of Lucene code shipped as part of this jar

[hakanai]

As Lucene bump major versions, we'll end up including more and more copies of the same code. But much of the code in lucene-core is not actually required to upgrade an index. (e.g., you wouldn't expect it to use a searcher or any queries.)

Find and destroy the bits of the Lucene code which are definitely not required to upgrade an index and record somewhere which bits could be deleted, so that the next version can have the same bits deleted.