Adjusts widths and padding in lots of places.

Makes teh whole page a bit wider to account for two columns of potentially long
text. Reduces the number of places with padding to make the spacing more
consistent with the Susy grid we have set up.

Also centers our logo in the footer because, I dunno, it feels better.
Adds contextual information on move form.

Displays a message with the game title and source move a user is making a move
on. This could be more elegant or informative. For instance, we could consider
replicating the Game Info section we already have on the single game and single
move pages.

Refs #69.
Removes heading for game.

Added that information in 80196d39.