pull changes from master to dev on 2014-04-07

This update brings these approved pulls to the dev branch, so they can be tested on dev.buttonweavers.com:
* #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