Accordion: Add demo showing removal of corner classes
Autocomplete: Add demo showing removal of corner classes
Dialog: Add demo showing removal of corner classes
Menu: Add demo showing removal of corner classes
Selectmenu: Add demo showing removal of corner classes
Progressbar: Add demo showing removal of corner classes
Slider: Add demo showing removal of corner classes
Spinner: Add demo showing removal of corner classes
Tabs: Add demo showing removal of corner classes
Tooltip: Add demo showing removal of corner classes
Menu: fix incorrect default classes value