title: Delegate event in vue
body: <p>Im trying to delegate an avent from one instance to another.</p>
  
  <p>I have a toolbar on the top of the page with a button like this</p>
  
  <pre><code>&lt;div id="toolbar"&gt;
  &lt;button v-on:click="add" class="btn btn-default" type="submit"&gt;&lt;span class="glyphicon glyphicon-plus" aria-hidden="true"&gt;&lt;/span&gt; Ny&lt;/button&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p>This add event working in this vue instance</p>
  
  <pre><code>var toolbarApp = new Vue({
      el: '#toolbar',
      data: {
  
      },
      methods: {
          add: function (event) {
              alert('lol');
          }
      }
  });
  </code></pre>
  
  <p>But now i want to attach this add event to another instance like this</p>
  
  <pre><code>var contactApp = new Vue({
      mixins: [toolbarApp],
      el: '#contact',
      data: {
          showGrid: true,
          showForm: false,
          editMode: false
      },
      created: function () {
          this.getContacts();
      },
      methods: {
          getContacts: function () {
              $.getJSON(this.apiGrid, function (data) {
                  this.contacts = data;
              }.bind(this));
          },
          add: function (event) {
              alert('hej');
          }
      }
  });
  </code></pre>
  
  <p>But i cant attach this because of diffrent instance. Is it any way to do this?
  Have also tried with mixedin with no luck.</p>
  
  <p>Thanks in advice</p>