Improved user experience for drop down widgets on touch devices

Before this PR, when selecting an item in the popup of a drop down widget (such as a DatePicker, an AutoComplete, a SelectBox or a MultiSelect), the focus goes back to the input element.

On touch devices, focusing an input element triggers the display of the keyboard. This PR prevents the focus from going back to the input element immediately after selecting an element in the popup of a drop down widget on touch devices or when touching the dropdown icon.

The behavior is not changed on non-touch devices (the detection of touch devices is done through `aria.utils.Device.isTouch`).
The signature and comments are copied from `aria.widgets.form.TextInput`. Wouldn't it be better to simply say it's overridden and to look into the parent classes for further information? And regarding the arguments list, since it's just forwarded to the parent class method call, same thing: not declaring them and using `.apply(this, arguments)`?