SOLR-4592: DefaultSolrCoreState#doRecovery needs to check the CoreContainer shutdown flag inside the recoveryLock sync block.

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/branches/lucene_solr_4_2@1458123 13f79535-47bb-0310-9956-ffa450edef68
SOLR-4595: CachingDirectoryFactory#close can throw a concurrent modification exception.

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/branches/lucene_solr_4_2@1458127 13f79535-47bb-0310-9956-ffa450edef68