anagrams: Add a "Noe, I'm done" button to the "Still playing?" dialog

anagrams: Add a "Noe, I'm done" button to the "Still playing?" dialog

This just dismisses the dialog.

I think it's important to add this because when theh dialog pops up it
triggers a natural reaction to want to click something to make it go
away. But when it hhas only one button, and that button isn't what you
want, it's mildly unnerving to just sit there and watch the countdown.

Much better to let the player answer the question the game is asking.