Add 'sprites' task to grunt that builds packed sprite sheets from the images in data/, and places the result in images/.
 - Same metadata as the other game assets, no block and different sources for sprites.
Go back on using hierarchical paths in texture naming.  Too many references to touch, just collapse all the directories into single file name references as before in the sprite map meta data.
Add missing ui spritesheet in gruntfile.
Fix issue where spritesheets weren't rebuilt on file change.
Add support for multiple sprite sheets while maintaining single file naming for textures.
Add support for scaling up images when generating sprite sheets.  Hardcode to 2x scale for now (32x32 sprites)
 - Simplify animation frame calculation because bin packed spritesheets don't rotate or wrap lines on single images.
Update Sprite Packer documentation and cleanup the implementation to properly use async notifications for completion. (Q)
Update Preloader to accept an array of sources to load. Clean up Gurk constructor and image preloading.
 - Add Util.isArray helper
Remove most screensize dependent images, and just scale the source size images to fit.
 - Exceptions are button images and screen overlay, which depend on higher resolution images to look slick.
 - This removes the dependency on the old generated sprite sheets, which are now removed.
 - Move ButtonGrid out into its own class (oops missed this earlier)
Scale up demo 512x, and tidy up the HTML page.
Update README.md to reflect node/grunt build setup instructions.
Update grunt watch, and support for heroku node app deployment.
 - Add express server for development usage (port is set to to 5215)

 Heroku
 - Use express server in deployed heroku env.
 - Add Procfile for heroku deploy.
 - Move grunt/express into dependencies so they're available on heroku
Cleanup sound playing and gruntfile configs.
 - Toggle sound on in gurk constructor if the setting is enabled.
 - Cleanup toggle to remove dep on Web UI link.
Add Travis-CI support for build verification, and chop up README.md to only reflect this fork's intent.