Add Node tools for sprite-sheet generation
NEW: Use AssetLoader and sprite sheets for better texture management
Reorganised code, slightly
REFACTOR: Reorganised code using RequireJS and Bower
NEW: Added terrainLayer, always at the bottom, so that other worldLayer items are displayed on top.
NEW: Added basic Agent implementation (a random walker)
REFACTOR: Major refactoring, breaking most spaghetti code into classes
Add dependencies to gh-pages version