Add advanced documentation examples

[martey]

There are a number of advanced features of the Graph API which it would helpful to have examples of in the documentation. These include:

• [ ] adding tags to an uploaded photo
• [ ] updating an existing photo
• [x] pagination (see #85)
• [ ] searching public posts
• [ ] realtime API updates

[ar-anvd]

@martey

How about targeting and feed_targeting when posting? This type of things are not clear how to use in docs about put_object, btw

https://stackoverflow.com/questions/44856841/create-wall-post-and-include-privacy-settings-based-on-localization