The use of locks in the LDAP provider could be improved.

NamingEventNotifier: rename finalize() to cleanup(). cleanup() is always called
   before the thread exits (in finally clause) so no need for a finalize()

EventSupport: removeDeadNotifier() needs sync in case 'notifiers' is not
    completely constructed before this method is called (consistent with other
    access of 'notifiers';
    - fireUnsolicited() and cleanup() needs sync because they access unsolicited
    and notifiers
Connection:
    - abandonRequeset(), ldapUnbind(): move synchronized closer to shared
      data access
    - replaceInputStream(), run(): expanded scope of synchronized to include
update of inStream
    - Removed finalize(); thread's finally clause already calls cleanup()
LdapClient:
    - finalize(): call forceClose() instead of close()
    - added internal version of getSearchReply() that skips some checks and setup
    - 'unsolicited' now initialized by default (instead of on-demand)
    - *Unsolicited() methods synchronize on 'unsolicited' instead of LdapClient
      to prevent possible deadlock

LdapCtx:
    - reconnect(): removed synchronized modifier (not needed)
    - synchronize access to clnt.referenceCount and closing connection
    - *Unsolicited() methods synchronize on eventSupport instead of LdapCtx;
      syncing on LdapCtx is problemmatic when caller syncs on Context (prevents
      firing of Unsolicited Notifications).