https://github.com/angular-ui/ui-select/wiki/ui-select-match
快速示例：
<ui-select-match allow-clear="true" placeholder="Select or search a country in the list...">
<span>{{$select.selected.name}}</span>
</ui-select-match>
快速示例：
<ui-select-match allow-clear="true" placeholder="Select or search a country in the list...">
<span>{{$select.selected.name}}</span>
</ui-select-match>
