We now leniently try to lookup DefaultParameterNameDiscoverer and create an instance of it to make use of Spring 4's improved parameter name capabilities on Java 8. We fall back on a LocalVariableTableParameterNameDiscoverer if on Spring versions prior to 4.
Reverted from ConcurrentHashMap to plain HashMap where concurrency wasn't an issue and profiling showed performance hotspots. Introduced caches for ParameterizedTypeInformation.getComponentType() and the resolved raw type in TypeDiscoverer.
So far the property lookup of a nested property path (e.g. "foo.bar") failed in cases the head property was not cached already. We now recursively resolve the type information even for an unpopulated cache.
