init new example class before each example is run

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/trunk@1628399 13f79535-47bb-0310-9956-ffa450edef68
LUCENE-5938: Add a new sparse fixed bit set and remove ConstantScoreAutoRewrite.


git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/trunk@1628402 13f79535-47bb-0310-9956-ffa450edef68
create all indexes w/ OpenMode.CREATE in facet demos

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/trunk@1628410 13f79535-47bb-0310-9956-ffa450edef68