title: ModelForm widget assignment not working in meta class
body: <p>I am trying to set a widget for a field in a ModelForm. I'd like to set it in the <code>class Meta</code> section with the other overrides but this doesn't seem to work:</p>
  
  <pre><code>class Meta:
      model = Client
      fields = ['name',]
      widget = {
          'name': forms.TextInput(attrs={
              'class': u'form-control'})
      }
  </code></pre>
  
  <p>Only this works:</p>
  
  <pre><code>name = forms.CharField(widget=forms.TextInput(attrs={
                               'class': u'form-control'}))
  class Meta:
      model = Client
      fields = ['name',]
  </code></pre>
  
  <p>Other overrides, like labels, error_messages etc. all work when specificed in the Meta class. </p>
  
  <p>How should I define a wdiget in the Meta class to get it working as above.</p>