Make compatible with Edit module

Currently the edit module breaks when there are viewfields present, I'm not sure but I'm guessing this has to do with the nested editable fields.

This can be fixed by setting #skip_edit to TRUE on the fields so that it's present in hook_preprocess_field where edit module attaches its html properties. Display suite did this in http://drupal.org/node/1896550

I'm guessing this could be done somewhere earlier than hook_field_attach_view_alter(), but I have no clue about where.

Currently I'm using the following snippet to make it compatible.

function hook_field_attach_view_alter(&$output, $context) {
  foreach (element_children($output) as $field_name) {
    $element = &$output[$field_name];
    if ($element['#field_type'] == 'viewfield') {
      $element['#skip_edit'] = TRUE;
    }
  }
}