Allow better control on the nodequeue table output

Hello,

the way the subqueue arrange form is displayed does not provide any easy way to alter its output. Basically if you need to add a column in this form array you need to totally override the default "nodequeue_arrange_subqueue_form_table" theme function, which is sad.

In my use case I wanted to add some informations linked to the node like its language and I had to rewrite the full theme function for changing just 3 lines of code. So I suggest adding this little alteration entry to allow other modules adding their specific needs easily. For example in my case I only had to add a few lines to handle the thing:

function [MY_MODULE]_nodequeue_arrange_subqueue_form_alter(&$form, &$header, &$rows) {
  // Insert the language column.
  array_splice($header, 1, 0, t('Language'));

  $current_row = 0;
  $languages = locale_language_list('name');
  foreach (element_children($form) as $key) {
    array_splice($rows[$current_row]['data'], 1, 0, t($languages[$form[$key]['#node']['language']]));
    $current_row++;
  }
}

Maybe this can be implemented differently but here is a first suggestion :)