IoSession and sessionClosed callback in MINA 2.0

[Matthew Phillips]

While porting to MINA 2.0 I've had a few tests fail that depend on the  
IoHandler.sessionClosed callback. It appears that if the acceptor  
closes a session in its IoHandler, the connector's IoHandler does not  
get a session close event.

The attached tests demonstrate this: the one ending in MINA 1.1 works  
fine under MINA 1.1.5, the one ending in MINA 2.0 (which is a direct  
port of the 1.1 test to the MINA 2.0 API) does not: the sessionClosed  
method is not called when the acceptor closes its end.

Hope someone can either explain why my understanding of how this is  
supposed to work is wrong or have a look at how MINA 2.0 handles this.

Cheers,

Matthew.