wrap component multicaster functionality into adapter pattern [patch]

the component multicaster functionality was removed form the PicoContainer interface, and classes that depend on it have to link to the DefaultPicoContainer class. To promote interoperability, I've written a ComponentMulticasterPicoAdapter, that is able to add multicaster functionality to any PicoContainer implementation.

To keep the contract of the exisitng implementation, I had to add a method to the PicoContainer interface: List getUnmanagedInsntaces().
There were few different ways of approaching the problem of unmanged componetns, and I'm not sure if I've chosen the right one.