Incorporated select field

Sample schema:
{ type: "select", name: "field_name", label: "Label", options: [ [1, "Option 1"], [2, "Option 2"] ], selected: 2, empty: true }

Custom options:
- options: [ <[id, value]> ] => options array
- selected: id => preselected value
- empty: true|false => show the empty value (false by default)