Added to the TODO automatic actions that should be implicitely done by Session

Moved some TODO items to the Middleware section where they belong

darcs-hash:20090206162038-58252-dc5891ff0e48774c2e5aba71a2e1c313e632d286
Implemented posting a number of SCSession* notifications that the application could be interested in

darcs-hash:20090206152134-58103-c5c5c602038232d85fa2afe258d1a8e9d709fd0f