LUCENE-5610, Lucene's Terms API now exposes min and max terms in
each field. I think we can use this in our term/numeric range
query/filters to avoid visiting a given segment by detecting up front
that the terms in the segment don't overlap with the query's range.
Even though block tree avoids disk seeks in certain cases when the
term cannot exist on-disk, I think this change would further avoid
disk seeks in additional cases because the min/max term has
more/different information than the in-memory FST terms index.