Moved createTemp* to LuceneTestCase, removing it from SolrTestCaseJ4. Created common infrastructure that creates temporary files and folders under the suite's master folder. Created a rule that cleans up afterwards (or provides an explicit message if something fails to clean up).:

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/branches/solr5914@1584832 13f79535-47bb-0310-9956-ffa450edef68