[BUG #7273] Fixed gradient for IE < 10
Removed empty namespace.
[BUG #7273] Added CSS class handling to html.Element.
[BUG #7273] Minor fix
[BUG #7273] Use CSS styles for decorator mixins
[BUG #7273] Don't apply a box shadow if necessary values are missing
[BUG #7273] Use CSS class API for custom CSS classes.
[BUG #7273] Added a global stylesheet for qx.desktop.
[BUG #7273] Use the global stylesheet for decorations
[BUG #7273] Fixed theme switch.
[BUG #7273] Use global stylesheet for abstract field.