SOLR-5596: Set system property zookeeper.forceSync=no for Solr test cases

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/branches/branch_4x@1608559 13f79535-47bb-0310-9956-ffa450edef68
SOLR-5596: Remove initCore call from afterClass

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/branches/branch_4x@1608565 13f79535-47bb-0310-9956-ffa450edef68