Better prevention of wrongly computed thumbs-container-width with lazy thumbnails
This is a fix for commit "5ed3ca89748aa6302cd294f207696e2abb521266".
This commit made sure that lazy loaded images are displayed "position:absolute" until they are loaded, in order to make sure they do not occupy space in the thumbscontainer. The side-effect  was (in IE 10) that images where displayed for a short time in the left corner of the container after loading, until the position was set to "relative" in "_carousel.update()".
This commit also uses the width of not-yet-loaded image containers for computing the total with of the thumbs-container and makes sure that these images get maximal height so that following images really have the expected position.