gistfile1.phtml

<?php
add_filter( 'smilies_src', 'cor_smilies_src', 1, 10 );
/**
 * Smilies
 *
 * @param unknown_type $img_src
 * @param unknown_type $img
 * @param unknown_type $siteurl
 * @return string
 */
function cor_smilies_src( $img_src, $img, $siteurl ) {
  $smilies = plugins_url( '/img/smilies/', __FILE__ ) . $img;
  return $smilies;
}