Sketch+Accessibility

This sample builds on the Sketch sample application to demonstrate a number of accessibility techniques including: * Use of an AccessibilityImageDescriptions.strings file * Overriding attributes programmatically and in Interface Builder * Creating a subclass to return a custom value description. In addition, the example also demonstrates making a more complex custom view, the graphic view of Sketch, accessible using the layout area suite of roles and attributes introduced in Snow Leopard.