corrects label of last time bracket (> lowerBound as opposed to > previous)
uses existing _timeBracketWidthInPercent variable for ChallengeGraph template
formatting: removes extra newline in ChallengeGraph
formatting: removes extra newline in header.css
increases grid size in ChallengeGraph
adds GameOver event in Game and subscribes to /game/game_over
adds logout confirmation message if the user has games in progress

(github - fixes #31)