title: angular 4.0.0 novalidate attribute
body: <p>After migrating to angular 4 a strange issue with my template-driven form has occured. My <code>required</code> attr on input seems to be broken. I suppose that  has <code>novalidate</code> attribute by default. But I need some html5 validations. Tried <code>novalidate="false"</code> but had no success.
  Is there some way to enable validation? Now it seems using reactive forms with its <code>Validators.required</code> is the only way.</p>
  
  <p>Thanks!</p>
  
  <p>My HTML component code snippet:</p>
  
  <pre><code>&lt;form (submit)="savePhone(phone);" novalidate="false"&gt;
  &lt;h3&gt;Новый телефон&lt;/h3&gt;
  &lt;md-input-container&gt;
      &lt;input mdInput placeholder="Номер телефона"
             onlyNumber="true" name="number"
             [(ngModel)]="phone.number" required&gt;
  &lt;/md-input-container&gt;
  &lt;md-select placeholder="Источник получения" (ngModel)="phone.source" name="source"&gt;
      &lt;md-option *ngFor="let source of sources" [value]="source"&gt;
          {{ source }}
      &lt;/md-option&gt;
  &lt;/md-select&gt;
  &lt;textarea name="comment" placeholder="Текст комментария"
            [(ngModel)]="phone.comment" name="comment"&gt;
  &lt;/textarea&gt;
  &lt;div layout="row" layout-align="end"&gt;
      &lt;button class="button button--success" type="submit"&gt;
          Добавить
      &lt;/button&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p></p>