pull changes from dev to production on 2014-04-11

This update brings these pulls, already on dev, to production:
* #762: add a second "Next game" link on the game display page
* #755: allow players to view full action and chat logs during a game, and make "full logs" the default view for a completed game
* #771: rename the Inactivity column for completed games
* #775: add player-visible explanations for a subset of invalid attacks

There are no database updates associated with this update.