removed style enforcement

Made the container end element styling enforcement optional, in case it was already set to a tolerable value.

The use case I had was that the images inside the container were centered vertically and stretched to fit the container width. The container was absolutely positioned. So after running the bare plugin I needed to get rid of position: relative on a container (absolute behaves in the same way, not 100% sure about fixed, but from brief tests it looks like it does) and remove top: 0 and left: 0 from image styles (they were set in the css file)