Add last_updated_at to Backbone Model toJSON

Adds a Moment date called last_updated_at representing the Rails
updated_at attribute to our prototype definition of toJSON on Models.

 On branch app_layouts
	modified:   app/assets/javascripts/backbone/lib/entities/models.js.coffee
Fix the last commit.

On branch app_layouts

	modified:   app/assets/javascripts/backbone/lib/entities/models.js.coffee
Add global cross browser logging capability.

Uses Ben Alman's debug library.

 On branch app_layouts
	modified:   app/assets/javascripts/application.js
	new file:   app/assets/javascripts/backbone/lib/utilities/logger.js.coffee
	new file:   vendor/assets/javascripts/ba-debug.js
Switched calls to console to App.log

 On branch app_layouts