field_has_data() will always return TRUE

Currently when determining if the EFQ in question is a 'has_data' query, the resulting collection is queried without checking the existence of the field in question, which results in a result that is always TRUE.

  if (mongodb_collection('fields_current', $entity_type)->find()->limit(1)->count(TRUE)) {
    return TRUE;  
  }

changing this to check for the existence of the field (meaning there is data present) fixes the issue:

  if (mongodb_collection('fields_current', $entity_type)->find(array($field['field_name'] => array('$exists' => TRUE)))->limit(1)->count(TRUE)) {
    return TRUE;
  }

Additionally it is looping through bundles and omitting that information in the query as well, should the bundle / type be included as well?

          foreach ($field['bundles'] as $entity_type => $data) {
            foreach($data as $bundle_name) {
              if (mongodb_collection('fields_current', $entity_type)->find(array($field['field_name'] => array('$exists' => TRUE), 'type' => $bundle_name))->limit(1)->count(TRUE)) {
                return TRUE;
              }
            }
          }

Patch for #3