Proposed Mailet v2 Interface

[Andrew C. Oliver]

package org.apache.mailet;

public interface Mailet {
   void create();
   void start();
   void stop();
   void destroy();

   Mail service(Mail mail);
}


Main changes I'd like to avoid this holdover from Avalon "Configurable" and
make configuration a matter of injection (so all MailetConfig is removed). 

I don't really see the need for the four stage lifecycle but this is 
basic CS stuff. 
I'm happy to remove create/destroy if there is consensus.

Generally I think Mailets will form chains.  It strikes me as a better 
model to not assume that the mail object going in is the one that is 
ultimately delivered to the next mailet in the chain.

Thoughts?

-Andy