undo the temp fix to kafka download url config, let's fix it properly
longer timeouts on start-up for a couple of entities (which may or may not need it...)
entity exposes getConfig(HasConfigKey)
support creating an entity from a spec which references only an impl,
but warn (useful for legacy classes and tests, being initialized in the new way)
tidy how AttributeSensorAndConfigKey gets converted from config to sensor
added failing test case for ConfigKey redeclared in interface bug
where one config key overwrites another, prefer the former; significant change in EntityDynamicType; fixes (failing) test cases for this problem introduced in previous commit
update uses of now-deprecated new BasicConfigKey(keyToOverwrite)
fix kafka so it sets jmx port correctly
fixes to version detection and location management, so that Kafka Integration tests pass
(and test cluster size 2)