o replaced LRUMap with ehCache instance (DIRSERVER-1992)
o protected saveContextCsn() with a semaphore
o updated the affected tests due to replacing LRUMap with ehCache instance


git-svn-id: https://svn.apache.org/repos/asf/directory/apacheds/trunk@1615303 13f79535-47bb-0310-9956-ffa450edef68
replaced the cache size to the default value (it was altered for testing purpose) (DIRSERVER-1992)


git-svn-id: https://svn.apache.org/repos/asf/directory/apacheds/trunk@1615304 13f79535-47bb-0310-9956-ffa450edef68