SOLR-5540: HdfsLockFactory should explicitly create the lock parent directory if necessary.

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/branches/branch_4x@1548592 13f79535-47bb-0310-9956-ffa450edef68
SOLR-5533: Improve out of the box support for running Solr on hdfs with SolrCloud.

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/branches/branch_4x@1548599 13f79535-47bb-0310-9956-ffa450edef68