Selectmenu: improve id generation
Selectmenu: don't quote click, remove extraneous space
Selectmenu: Comments start with an uppercase letter
Selectmenu: simplify tabindex attribute setting on button create
Selectmenu: set aria states as string if needed
Selectmenu: improve readability when creating button elements
Selectmenu: blank before comment
Selectmenu: rename var to focusIndex
Selectmenu: adjust comments, trim trailing spaces
Selectmenu: use guard clause for option length checking in refresh
Selectmenu: add spaces