Importing ListAction

Thanks, internet guy
(http://tips4java.wordpress.com/2008/10/14/list-action/)
Comment

Added comment
Start game from list

Now we can start playing games by double clicking OR hitting enter on
the list. Hooray!
Added "Return and Mark as Used" option

Intended as a troubleshooting/testing tool, mostly. Can exit a game that
is currently in progress, and it will mark the game as being used for
practise
mark games as used for practise

When we have called the endGame() method, we now mark that game as
having been used for practise