ACTIVEMQ6-36 Disallow SSLv3 for POODLE
ACTIVEMQ6-37 NoSuchMethodError during init

When compiled by JDK 8 targeting Java 6 and then run on JDK 6 or 7 the
ConcurrentHashMap#keyset() method can fail because the return types
changed in Java 8. Using ConcurrentMap interface to resolve the issue.
ACTIVEMQ6-38 Overzealous logging for missing queue
Merge PR #12 - fixes from apache