SOLR-4596: DistributedQueue should ensure its full path exists in the constructor.

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/branches/lucene_solr_4_2@1458142 13f79535-47bb-0310-9956-ffa450edef68
SOLR-4597: CachingDirectoryFactory#remove should not attempt to empty/remove the index right away but flag for removal after close. (Mark Miller)

SOLR-4598: The Core Admin unload command's option 'deleteDataDir', should use the DirectoryFactory API to remove the data dir.

SOLR-4599: CachingDirectoryFactory calls close(Directory) on forceNew if the Directory has a refCnt of 0, but it should call closeDirectory(CacheValue).

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/branches/lucene_solr_4_2@1458145 13f79535-47bb-0310-9956-ffa450edef68
fix typo

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/branches/lucene_solr_4_2@1458146 13f79535-47bb-0310-9956-ffa450edef68
SOLR-4602: ZkController#unregister should cancel it's election participation before asking the Overseer to delete the SolrCore information.

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/branches/lucene_solr_4_2@1458147 13f79535-47bb-0310-9956-ffa450edef68