binahstack

01. Added AutoRefreshController - will observe UIApplication.willEnterForeGround and invoke automatic refresh after a certain threshold (time delta from last successful data retrieval).

01. Added Networking layer with paging and prefetch support.

Added unit test according to assignment requirements - testing friendly time ago (for Date object) strings generation.

01. Added navigation bar button to switch between: "Answered" and: "UnAnswered" state.

01. refactoring question model according to StackOverflow API