WIP: CFD-151- Discussion message

#144 
```php
if (!empty($item['summary'])) {
  $image = _extract_image_from_text_field($item['summary']);
  $body_summary = _text_sanitize($instance, $langcode, $item, 'summary');
}
else {
  $image = _extract_image_from_text_field($item['value']);
  $body_summary = _text_sanitize($instance, $langcode, $item, 'value');
  $body_summary = text_summary($body_summary, $instance['settings']['text_processing'] ? $item['format'] : NULL);
}

function _extract_image_from_text_field($value) {
  if (strpos($value, '<img') && strpos($value, '<img') < 600) {
    $pattern = '/<img\s+[^>]*?src="([^"]+)"[^>]+>/i';
    preg_match($pattern, $value, $images_uri);
    // Getting the image url.
    $image_uri = $images_uri[1];
    // Removing the mage from the field value.
    $value = preg_replace('/<img[^>]+\>/i', '', $body);
  }
}
```