This converts individual objects passed in through the `array`
parameter to `<option>` tags when Select2 is initialized. This
removes a lot of duplicate code from the `ArrayAdapter`, and keeps
everything closer to the native `<select>` element.
This introduces a breaking change from previous versions of Select2,
where the initial value for array data was blank, even if a blank
option was not present in the original array of objects. Now the
first object passed in will be selected by default, following the
behavior of a standard `<select>` element.
This breaking change does not affect `<select multiple="multiple">`
elements, which by default have no selection.