Merge high_scores

:bar_chart: New AMD module highScores.js

:question: While highScores.add and highScores.view are contained within the same AMD module, they are treated as separate modules by the game. They each have their own shapes / layer / animation, and their transitions are independently handled by _transitionListener() in events.js.

:electric_plug: Add Backbone, Firebase, Backfire, and kineticjs-editable-text dependencies

:left_right_arrow: _transitionListener() in events.js is no longer a loop. It is now powered by Backbone change events.

:heavy_plus_sign: Hundreds of additional commits containing code style and organization improvements