Fix a NPE exposed in the tests and also reduce the class visibility of a couple of classes that were introduced in the previous commit (RemotingConnectionManager and RemotingEndpointManager)
EJBCLIENT-68 Fix potential ConcurrentModificationException while attempting reconnects through the EJBClientContext
EJBCLIENT-70 Fix scoping of EJB proxies returned by finder methods and getEJBHome method invocations. Similar to EJBCLIENT-51 issue