Export interfaces on the JAR
 - use eclipse -> right click on the project explorer, export, java,
JAR. Select the following classes: NavigationItem,
OnDataChangedListener, Discount, Store, WebServiceResultHandler
 - you can use this JAR to create extensions, with your module can: 
	- create navigation items (using NavigationItem interface)
	- subscribe to listening data changes to stores and discounts (using
OnDataChangedListener interface)
	- get responses from the web service (using WebServiceResultHandler
interface)
 - name the JAR air-interfaces and press finish
 - on this commit you can find it in the "extras" folder