Selectmenu documentation code example correction

[Eli-Handel]

By the code example for http://api.jqueryui.com/selectmenu/#option-classes, I think that it should say
"ui-selectmenu-menu": "highlight"
instead of
"ui-selectmenu": "highlight"
since "ui-selectmenu-menu" is the one that works (and it's the one that's listed at http://api.jqueryui.com/selectmenu/#theming)