fix imageZoom levels in MeasureBasedView (IIIF)
Relates to #262
When changing the zoom level in measureBasedView the image will be reloaded with the wrong dimensions. See here
Here also the footer is missing. This is problematic, because the dimensions are different then and the measures are moving caused by this.
@roewenstrunk I thought we had fixed this for 1.0.0-beta.4, can you imagine, why this occurs here again? Could this problem be caused by the IIIF-providing institution?