fix(spinner): add the refresh spinner to the select-multiple template

The multiple mode would not show a refresh spinner even with spinner-enabled set to true. Add the same spinner html from the single selection template to the multiple selection template.

Closes #1985

Author: yancymatherne

src/bootstrap/select-multiple.tpl.html

@@ -1,6 +1,7 @@
 <div class="ui-select-container ui-select-multiple ui-select-bootstrap dropdown form-control" ng-class="{open: $select.open}">
   <div>
     <div class="ui-select-match"></div>
+    <span ng-show="$select.open && $select.refreshing && $select.spinnerEnabled" class="ui-select-refreshing {{$select.spinnerClass}}"></span>
     <input type="search"
            autocomplete="off"
            autocorrect="off"