Implements hook_form_FORM_ID_alter() for block_custom_block_delete().
Adds node specific submit handler to delete custom block form.
node_form_block_custom_block_delete_submit()
function node_form_block_custom_block_delete_alter(&$form, &$form_state) {
$form['#submit'][] = 'node_form_block_custom_block_delete_submit';
}