SOLR-4573: Accessing Admin UI files in SolrCloud mode logs warnings.

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/branches/lucene_solr_4_2@1458130 13f79535-47bb-0310-9956-ffa450edef68
SOLR-4594: StandardDirectoryFactory#remove accesses byDirectoryCache without a lock.

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/branches/lucene_solr_4_2@1458134 13f79535-47bb-0310-9956-ffa450edef68