#2018 - Make ui.init.js thumbnail hover effect more robust.
- changed thumbnail hover effect to store its original height on mouseenter, then return to it on mouseleave.
- removed previous routine which depended on the height of its siblings and was incompatible with some IE versions.
Merge pull request #163 from shadlaws/fix_2018

#2018 - Make ui.init.js thumbnail hover effect more robust.