SOLR-4597: Because of Windows, we have to wait to delete the data dir after the SolrCore is closed.

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/trunk@1457816 13f79535-47bb-0310-9956-ffa450edef68
SOLR-4606: set the random seed used to shuffle shards within tests

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/trunk@1457821 13f79535-47bb-0310-9956-ffa450edef68