public int getId(String domain,
    String name)
Return an int ID for faster access. Will be used for notifications
and for other operations we want to optimize.

 public  void invoke(List mbeans,
    String operation,
    boolean failFirst) throws Exception
Invoke an operation on a set of mbeans.

 public List loadMBeans(Object source,
    ClassLoader cl) throws Exception
Load an extended mlet file. The source can be an URL, File or
InputStream. 

All mbeans will be instantiated, registered and the attributes will be 
set. The result is a list of ObjectNames.

 public  void loadMetadata(Object source) throws Exception
Load descriptors. The source can be a File, URL pointing to an
mbeans-descriptors.xml.

Also ( experimental for now ) a ClassLoader - in which case META-INF/ will
be used.

 public  void registerComponent(Object bean,
    String oname,
    String type) throws Exception
Register a bean by creating a modeler mbean and adding it to the 
MBeanServer.

If metadata is not loaded, we'll look up and read a file named
"mbeans-descriptors.ser" or "mbeans-descriptors.xml" in the same package
or parent.

If the bean is an instance of DynamicMBean. it's metadata will be converted
to a model mbean and we'll wrap it - so modeler services will be supported

If the metadata is still not found, introspection will be used to extract
it automatically. 

If an mbean is already registered under this name, it'll be first
unregistered.

If the component implements MBeanRegistration, the methods will be called.
If the method has a method "setRegistry" that takes a RegistryMBean as
parameter, it'll be called with the current registry.

 public  void stop()
Reset all metadata cached by this registry. Should be called 
to support reloading. Existing mbeans will not be affected or modified.

It will be called automatically if the Registry is unregistered.

 public  void unregisterComponent(String oname)
Unregister a component. We'll first check if it is registered,
and mask all errors. This is mostly a helper.