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

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/branches/lucene_solr_4_6@1557848 13f79535-47bb-0310-9956-ffa450edef68
clean up CHANGES

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/branches/lucene_solr_4_6@1557852 13f79535-47bb-0310-9956-ffa450edef68