[BUG #7273] Fixed knob positioning
[BUG #7273] remove pseudo element styles
[BUG #7273] fixed HtmlArea sizing
[BUG #7273] fixed height calculation for wrap in IE8
[BUG #7273] fixed height calculation for wrap in IE8
[BUG #7273] fixed scaled image positioning for IE8
[BUG #7447] Fixed event handling if content elements are switched