merge two items to be rendered in item_list

merge item_list items.php

$variables['planning'] = array(
  '#theme' => 'item_list',
  '#items' => array(),
  '#attributes' => array(
    'class' => 'icons-info unstyled floated',
  )
);

$all_terms = array_merge($variables['field_bbcgf_planning'], $variables['field_bbcgf_diet'], $variables['field_bbcgf_healthy']);

$easily_doubled_key = null;
$easily_halved_key = null;

foreach ($all_terms as $key => $term) {
  $term_name = $term['taxonomy_term']->name;
  // Take the taxonomy term name, make lowercase and replace space with a dash to use as a css class
  $term_css = strtolower(str_replace(" ", "-", $term_name));

  // Two values that need to be merged into one item
  if ($term['taxonomy_term']->name == 'Easily doubled') {
    $easily_doubled_key = $key;
  } else if ($term_name == 'Easily halved') {
    $easily_halved_key = $key;
  }

  $variables['planning']['#items'][$key] = array(
    'data' => t('<i class="icon-small icon-' . $term_css . '"></i>' . $term_name),
    'class' => array('class' => $term_css,),
  );
}

if ($easily_doubled_key && $easily_halved_key) {

  $term_name = t('Easily doubled<br/>Easily halved');

  $variables['planning']['#items'][$easily_doubled_key] = array(
    'data' => t('<i class="icon-small icon-easily"></i>' . $term_name),
    'class' => array('class' => 'easily',),
  );

  unset($variables['planning']['#items'][$easily_halved_key];
}