title: Use field label as placeholder in django-crispy-forms
body: <p>I'm thinking about the DRY way to use field labels for placeholder attribute of my <code>&lt;input&gt;</code> HTML elements. I'm using <code>django-crispy-forms</code>.</p>
  
  <p>Right now I have:</p>
  
  <pre><code>class FilterForm(Form):
  
      query = CharField(max_length=50, label='', required=False)
  
      def __init__(self, data=None, files=None, **kwargs):
          self.helper = FormHelper()
          self.helper.layout = Layout(
              Field('query', placeholder='Search ...'),
          )
          super(FilterForm, self).__init__(data, files, **kwargs)
  </code></pre>
  
  <p>I'd prefer, however, not to have to set label and placeholder separately, as this for will eventually have many more fields and it's quite verbose.</p>
  
  <p>What are your suggestions?</p>