[Sticky] Dont Require Width/Height to be Set

[Jabark]

I've found an issue with the sticky module in that when it initialises it adds height and width to the element, and then when more components are loaded a scrollbar appears which causes the parent container to shrink, however the sticky element does not because it already has the width set to it. I have this issue currently within a Meteor application, however as a quick example of what happens, here's a fiddle to simulate it:

https://jsfiddle.net/3szcuj5z/5/

[jlukic]

I think it makes sense to set width/height setting as a setting. Some cases are actually helped by forcing the element to a width, as fixed position will cause width: 100% to apply differently.