add HashMapMap collection
add ReflectionManager

move package layout for reflection

ReflectionManager allows registering INonApiHandler's for specific NMS versions and will return the one for the current NMS version.

ReflectionManager requires the compatible NMS versions in its constructor. If the current NMS version is not compatible, the ReflectionManager's owning plugin will be disabled. This can be overridden by the server operator via the plugins config (Assuming the plugin extends GenericsPlugin)