Faux 'position: sticky' module 

Needed a simple js 'position sticky' module for a MPU test

Also, often we need access to the non-debounced window events (scroll, etc), so removed it from the mediator events, and moved the onus on the listener to throttle/debounce
Always wondered why debounce? It defaults to trailing edge, whereas throttle defaults to leading edge. Does that mean you're already 200ms late?