Lazy binding

Support for lazy binding of elements. 

When binding objects, if a root element has the property "lazy" set to true/YES then its sections and sub elements will not be bound (only its properties will be bound). This is very useful for dynamic data, for example.

See lazybind.json in the sample app. The sample will load data from github, much like the "remote files" sample, however, this sample is able to navigate through the rest API by following URLs and lazy-binding on responses.

This is also very useful for working with very deep nested data that needs to be updated. Instead of reloading the entire nested element hierarchy it's possible to load the minimal data necessary for the currently visible elements.

EDIT:

Forgot to mention. In addition to binding lazy, this will also result in the elements being build in a lazy way as well.