title: How to clear ui-select programmatically?
body: <p>I would like to find a way to clear the selection of a ui-select by code.</p>
  
  <p>For example I have the following code</p>
  
  <pre><code>&lt;ui-select ng-model="selectedCustomerCode" ng-if="CustomerIds.length&gt;1" on-select="CustomerCodeFiltersOnSelectCallback($item, $model)" theme="bootstrap"&gt;
    &lt;ui-select-match class="ui-select-match" allow-clear="true" placeholder="Επιλογή κωδικού πελάτη..."&gt;{{$select.selected.CCode}}&lt;/ui-select-match&gt;
    &lt;ui-select-choices class="ui-select-choices" repeat="customer in CustomerIds | propsFilter: {CCode: $select.search}"&gt;
      &lt;div ng-bind-html="customer.CCode | highlight: $select.search"&gt;&lt;/div&gt;
    &lt;/ui-select-choices&gt;
  &lt;/ui-select&gt;
  </code></pre>
  
  <p>I want to clink on a clear button and clear some inputs including the ui-select.
  What is the code in order to clear ui-select?</p>